Introduction: Little is known about the quality of healthcare in intensive care units (ICUs) in Poland. Data on patients hospitalized in ICUs in Warsaw and the results of their treatment are scarce. This information, ...Introduction: Little is known about the quality of healthcare in intensive care units (ICUs) in Poland. Data on patients hospitalized in ICUs in Warsaw and the results of their treatment are scarce. This information, crucial for improving the quality of ICU healthcare services, is not collected routinely. Quality indicators are essential in the concept of holistic quality management. Implementation of these indicators in ICUs is a complex and time-consuming process. Systematic increase in demand for quality assessment tools that can reflect real conditions of the practices of ICUs, prompts the search for effective solutions. Methods: The study included 12,155 patients hospitalized in 16 ICUs of Warsaw hospitals (8 ICUs, n = 3293 of the first level of care, and 8 ICUs, n = 8862 of the second level) between 1<sup>st</sup> January 2017 and 31<sup>st</sup> December 2018. ICUs in pediatric and oncological hospitals were excluded from the study. Characteristics and demography of patients as well as the structure, treatment and human resources of the ICUs in Warsaw were analyzed. Length of stay, unexpected extubations, nosocomial infections, ICU readmissions and standardized mortality ratios (SMR) were retrieved from National Health Fund, Ministry of Health, and other public databases. Results: In primary level ICUs patients’ age (66.42 vs. 64.43 years;p = 0.005) and comorbidity rate (30.56% vs. 22.78%, p = 0.037) were higher when compared to ICUs of the second level of care. The crude mortality rate in ICUs in Warsaw was significantly higher than in other EU countries and differed between ICUs of the first and the second level (34.77% vs. 24.53%, respectively;p = 0.004). SMRs were however very low: 0.71 and 0.64 (ns), respectively. ICU readmission rate, unexpected extubations, central catheter related infections, and length of stay were identical in both groups. More patients were admitted to ICU form emergency department and/or discharged home in Level 1 ICUs (18.9% vs 12.9%, p Conclusions: There are no major differences in quality of care provided by Level 1 and Level 2 ICUs in Poland, although more rigorous adhesion to admission and discharge policies is needed. Implementation of the instruments for assessing quality of ICUs including benchmarking, self-assessment of departments and evaluation of changes resulting from audits according to the Deming cycle is of utmost importance. Standardization of quality measures and markers, communication, and cooperation in reporting and creation of ICU medical registers is necessary to improve the quality of healthcare.展开更多
In present days,our instable financial markets,characterized by heavier growing monetary responsibilities,are delivering and enlarging ever growing central banks’functions.The financial stability applied standards ha...In present days,our instable financial markets,characterized by heavier growing monetary responsibilities,are delivering and enlarging ever growing central banks’functions.The financial stability applied standards have been creating contradictory results in the recent Great Recessions since the year 1987 up to the central banks model,after the 2008 last financial crisis,with major central banks as the FED and the CEB(Diamond,2007,pp.189-200)conflicting main operative areas,monetary and financial goals with unexpected results.We have been living a very difficult and dramatic period,which suggests a lot of reconsiderations about what the monetary policy means and may pursue and in which area,with respect to the financial system restrictions,in particular,during the post-second World War,based initially on the pseudo gold dollar parity,things were relatively stable and major financial crises were happening in emerging peripheral markets only.Financial stability was ever relevant,but it was not something to which governments devoted institutional attention.Based on what happened during the recent crisis,it is now of capital responsibility connecting monetary and economic financial stability jointly.Central banks,on the contrary,seem not able to pursue both functions relying on classical market tools.Up to now,the only obligation,imposed to a central bank as a private agent,has been taking care of monetary stability,to contain inflation rates over upper limits,assumed in entering definitely in the legal tender monetary,regime almost everywhere over the planet.Originally,for specific monetary policy purposes alone,between central banks and possible financial entities,there were no guidelines or structural determined controls,only institutional and statutory single bank’s operational clauses.There were no legal constraints such as formal loan to-value,or loan to cash-flows,or formal capital level limits,based on actual constraints.Free repurchase agreements and sales or purchases of securities(the most relevant tools of monetary policy guidelines),generally based on private financial covenants,were the sole most recurrent tactical interferences in adjusting the economic free activity.The assuming statutory thresholds were casual in the incorporating state,central banks used to monitor the activities of agents through economic incentives,rather than mandating and monitoring specific legal prescriptions.The evolving inconsistency of both activities has become even more manifest;two conditions should be fulfilled simultaneously:To avoid dilemmas in which a central bank might be called to make the autonomous independent management choice between monetary price stability,pursuing at same time,generally incompatible,financial stability,two different policies should be rarely jointly assigned to same bodies,especially central banks.As regards the first issue,the IMF nevertheless,with Brunnermeier and Sannikov(Brunnermeier&Sannikov,2012),has argued that price stability and financial stability are interlinked Short-term debt financing played an important role in the run-up to the financial crisis,as increases in leverage helped boost growth but also made the economy more susceptible to a downturn.Since the recession,private agents have reduced their debt level while many governments have increased borrowing.This deleveraging process appears to be holding back the recovery,and the Japanese experience suggests that such deleveraging can continue over an extended period”,unless in the long run we are all broken at state level,as history seems now to prove.It is true indeed,as reminded by Lamfalussy(Lamfalussy et al.,2010,pp.7-9),and now widely proved by facts,that prices and the growth-employment objectives,run into each other because it is seldom the case that the pursuit of one is consistent with the pursuit of the second in global economies.展开更多
A present monetary theory of the Great Depression has been explained as stemming from Milton Friedman,ignoring the previous Davanzati,a Florentine finding,in the 16th Century,an explanation solution to the increase of...A present monetary theory of the Great Depression has been explained as stemming from Milton Friedman,ignoring the previous Davanzati,a Florentine finding,in the 16th Century,an explanation solution to the increase of prices due to the arrival of Spanish silver from the New World.Designed to counter the Keynesian notion that the Depression resulted from instability theories,characterizing most modern capitalistic economies,Friedmans explanation identified lately the monetary trend as a disordered monetary policy,carried out by erroneous Federal Reserve Board interventions,possible after the Aldrich-Vreeland innovations,introducing Treasury money in the year 1908.More recent works about the Great Depression reconsider the attempts to restore the international gold standard,suppressed on the brink of World War I.We learnt that current views of the Depression,as analyzed in the 1920s by Ralph Hawtrey and Gustav Cassel,while recommending a gold standard reset,reflect that such standard risk deflations,unless the resulting increase in the international monetary demand linked to physical gold,could be satisfied.Although their early warnings of potential disaster became actual and their policy advice was consistently correct,their contributions were ignored and forgotten.The vanishing of their comments was firstly outlined not a long time ago,by Batchelder and Glasner What Ever Happened to Hawtrey and Cassel? (2013)This paper explores the possible reasons for the remarkable historical disregard of the Hawtrey-Cassel monetary explanation of the Great Depression,even by Nobel Prize winner Robert Mundell in his 2000 historical Nobel reconsideration of the monetary 20th century(Mundell,2000).The paper stresses the identical historical conditions surfacing after the Bretton Woods agreements.Robert Triffin and Jacques Rueff comment likely warnings as in the first Great Depression,under the monetary policy illusion and the Central Banks excessive disregard of the basics of the quantitative theory on the long run,mostly ignored.Robert Triffin started to address the problem in March and June of 1959,Italian Banca Nazionale del Lavoro Quarterly Review.The first of these articles(Part One:Diagnosis)explains in the simplest possible terms,the extraordinary success of the nineteenth century system of international gold based convertibility,and the calamitous collapse of the late 1920s attempts to bring it back to life.It may hold for us today an indication of the main efforts facing the similar attempt at reconstructing the past expressed some 64 years later,after the first of August 1914,by Triffin during the 1978 Christmas weekend.To deal with them in simple,commonsense terms would inevitably classify the author as an unrealistic whose views deserve no more than a raising of eyebrows.Jacques Rueff,with his The Monetary Sin of the West,a logical consequence of the Triffin previous notes of the 1960s,went straight to the consequences of the Camp David resolutions of President Nixon who just temporarily asked his Treasury Secretary,John Conally to suspend the gold convertibility.There were two changes in United States(U.S.)government policy toward the monetary role of gold in the last 100 years.The first was in 1933-1934;all holdings of gold were confiscated in March 1933.Then,the U.S.Treasury adopted a parity for the U.S.dollar of$35.00 an ounce at the end of January 1934.Gold production surged,the private demand for gold fell,and the U.S.experienced large increases in foreign demand for U.S.dollar securities.In those years there was a massive flow of gold to the U.S.The second historical change in U.S.gold policy followed the meeting at Camp David on August the 15th 1971,when the U.S.Treasury closed its gold window fearing a run on its gold holdings,declining towards$10 billion.Some U.S.officials sought to diminish the monetary role of gold.The anticipation of some U.S.officials attending Camp David was that the persistent U.S.payments problem would disappear,once foreign currencies had no parities in terms of the U.S.dollar.The prices of these foreign currencies would increase and the U.S.trade surplus would become larger.Instead,many foreign Central Banks became larger buyers of dollarssecurities,which led to a higher price of the U.S.dollar and a U.S.trade structural deficit.The U.S.international investment position morphed from the worlds largest creditor country,to the worlds present day largest debtor.展开更多
Purpose:This study aimed to understand the joint standard of blood glucose,blood li-pids,and blood pressure in elderly patients>60 years of age with type 2 diabetes in the Beijing Yongding Road Community.Methods:On...Purpose:This study aimed to understand the joint standard of blood glucose,blood li-pids,and blood pressure in elderly patients>60 years of age with type 2 diabetes in the Beijing Yongding Road Community.Methods:One hundred ninety-two elderly patients>60 years of age who were diagnosed with type 2 diabetes in Yongding Road Community served as the investigation subjects,under-went standard management,and the dynamic changes in blood glucose,blood lipids,and blood pressure were monitored for 48 months.Results:At the end of the observation period,the standard rates of fasting blood glucose and postprandial blood glucose were 72.55%and 80.00%,respectively,which were increased compared with 55.73%and 56.08%at baseline(P<0.01).The standard rate of HbA1c was 59.81%,which was increased compared with 53.44%at baseline(P>0.05).The standard rates of TG and LDL-C were 76.71%and 60.38%,respectively,which were increased compared with 54.69%and 34.74%at base-line,and the standard rate of HDL-C was 13.64%,which was decreased compared with 40.10%at baseline(P<0.01).The standard rate of BP was 58.33%,which was increased compared with 38.54%at baseline(P<0.01).The optimal control rate of blood glucose for 48 months(the standard times of the total measurement times in 48 months≥75%)was higher;the fasting blood glucose was 52.17%,the 2-h postprandial blood glucose was 60.22%,and the HbA1c was 46.45%.The optimal control rate of blood lipids was lower;LDL-C was 17.49%and HDL-C was 13.59%.The optimal control rate of BP was 9.13%.At the end of the observation period,the levels of fasting blood glucose and postprandial blood glucose were decreased by 0.7 mmol/L and 1.48 mmol/L,respectively,compared with the base-line(P<0.01).The level of HbA1c was decreased by 0.18%compared with the baseline(P<0.05).The levels of LDL-C and HDL-C were decreased by 0.4 mmol/L and 0.23 mmol/L,respectively,compared with the baseline(P<0.01).The levels of SBP and DBP were decreased by 4 mmHg compared with the baseline(P<0.01).At the end of the observation period,the joint standard rate of the three indices of HbA1c,LDL-C,and BP was 24.72%,which was increased compared with 6.25%at baseline(P<0.01).Conclusion:Standardized management of elderly patients with diabetes in the Community can improve the joint standard rate of blood glucose,blood lipids,and blood pressure.The op-timal control rate and joint standard rate are the important indices for evaluating the quality of diabetes management.展开更多
Trait specialization often comes at the expense of original trait function,potentially causing evolutionary tradeoffs that may render specialist populations vulnerable to extinction.However,many specialized adaptation...Trait specialization often comes at the expense of original trait function,potentially causing evolutionary tradeoffs that may render specialist populations vulnerable to extinction.However,many specialized adaptations evolve repeatedly,suggesting selection favors specialization in specific environments.Some garter snake(Thamnophis)populations possess specialized mutations in voltage-gated sodium channels that allow them to consume Pacific newts(Taricha)defended by a highly potent neurotoxin(tetrodotoxin).These mutations,however,also decrease protein and muscle function,suggesting garter snakes may suffer evolutionary tradeoffs.We measured a key physiological process,standard metabolic rate(SMR),to investigate whether specialized adaptations in toxin-resistant garter snakes affect baseline energy expenditure.In snakes,skeletal muscles influence metabolism and power ventilation,so inefficiencies of sodium channels in these muscles might impact whole-animal energy expenditure.Further,because sodium channels are membrane-bound proteins,inefficiencies of channel kinetics and performance might be exacerbated at suboptimal temperatures.We measured SMR in 2 species,Thamnophis atratus and Thamnophis sirtalis,that independently evolved tetrodotoxin resistance through unique mutations,providing replicate experiments with distinct underlying genetics and potential physiological costs.Despite our expectations,neither resistance phenotype nor sodium channel genotype affected metabolism and resistant snakes did not perform worse under suboptimal body temperature.Instead,T.atratus and T.sirtalis show nearly identical rates of mass-adjusted energy expenditure at both temperatures,despite differing eco-morphologies,life histories,and distant phylogenetic positions.These findings suggest SMR may be a conserved feature of Thamnophis,and that any organismal tradeoffs may be compensated to retain whole-animal function.展开更多
文摘Introduction: Little is known about the quality of healthcare in intensive care units (ICUs) in Poland. Data on patients hospitalized in ICUs in Warsaw and the results of their treatment are scarce. This information, crucial for improving the quality of ICU healthcare services, is not collected routinely. Quality indicators are essential in the concept of holistic quality management. Implementation of these indicators in ICUs is a complex and time-consuming process. Systematic increase in demand for quality assessment tools that can reflect real conditions of the practices of ICUs, prompts the search for effective solutions. Methods: The study included 12,155 patients hospitalized in 16 ICUs of Warsaw hospitals (8 ICUs, n = 3293 of the first level of care, and 8 ICUs, n = 8862 of the second level) between 1<sup>st</sup> January 2017 and 31<sup>st</sup> December 2018. ICUs in pediatric and oncological hospitals were excluded from the study. Characteristics and demography of patients as well as the structure, treatment and human resources of the ICUs in Warsaw were analyzed. Length of stay, unexpected extubations, nosocomial infections, ICU readmissions and standardized mortality ratios (SMR) were retrieved from National Health Fund, Ministry of Health, and other public databases. Results: In primary level ICUs patients’ age (66.42 vs. 64.43 years;p = 0.005) and comorbidity rate (30.56% vs. 22.78%, p = 0.037) were higher when compared to ICUs of the second level of care. The crude mortality rate in ICUs in Warsaw was significantly higher than in other EU countries and differed between ICUs of the first and the second level (34.77% vs. 24.53%, respectively;p = 0.004). SMRs were however very low: 0.71 and 0.64 (ns), respectively. ICU readmission rate, unexpected extubations, central catheter related infections, and length of stay were identical in both groups. More patients were admitted to ICU form emergency department and/or discharged home in Level 1 ICUs (18.9% vs 12.9%, p Conclusions: There are no major differences in quality of care provided by Level 1 and Level 2 ICUs in Poland, although more rigorous adhesion to admission and discharge policies is needed. Implementation of the instruments for assessing quality of ICUs including benchmarking, self-assessment of departments and evaluation of changes resulting from audits according to the Deming cycle is of utmost importance. Standardization of quality measures and markers, communication, and cooperation in reporting and creation of ICU medical registers is necessary to improve the quality of healthcare.
文摘In present days,our instable financial markets,characterized by heavier growing monetary responsibilities,are delivering and enlarging ever growing central banks’functions.The financial stability applied standards have been creating contradictory results in the recent Great Recessions since the year 1987 up to the central banks model,after the 2008 last financial crisis,with major central banks as the FED and the CEB(Diamond,2007,pp.189-200)conflicting main operative areas,monetary and financial goals with unexpected results.We have been living a very difficult and dramatic period,which suggests a lot of reconsiderations about what the monetary policy means and may pursue and in which area,with respect to the financial system restrictions,in particular,during the post-second World War,based initially on the pseudo gold dollar parity,things were relatively stable and major financial crises were happening in emerging peripheral markets only.Financial stability was ever relevant,but it was not something to which governments devoted institutional attention.Based on what happened during the recent crisis,it is now of capital responsibility connecting monetary and economic financial stability jointly.Central banks,on the contrary,seem not able to pursue both functions relying on classical market tools.Up to now,the only obligation,imposed to a central bank as a private agent,has been taking care of monetary stability,to contain inflation rates over upper limits,assumed in entering definitely in the legal tender monetary,regime almost everywhere over the planet.Originally,for specific monetary policy purposes alone,between central banks and possible financial entities,there were no guidelines or structural determined controls,only institutional and statutory single bank’s operational clauses.There were no legal constraints such as formal loan to-value,or loan to cash-flows,or formal capital level limits,based on actual constraints.Free repurchase agreements and sales or purchases of securities(the most relevant tools of monetary policy guidelines),generally based on private financial covenants,were the sole most recurrent tactical interferences in adjusting the economic free activity.The assuming statutory thresholds were casual in the incorporating state,central banks used to monitor the activities of agents through economic incentives,rather than mandating and monitoring specific legal prescriptions.The evolving inconsistency of both activities has become even more manifest;two conditions should be fulfilled simultaneously:To avoid dilemmas in which a central bank might be called to make the autonomous independent management choice between monetary price stability,pursuing at same time,generally incompatible,financial stability,two different policies should be rarely jointly assigned to same bodies,especially central banks.As regards the first issue,the IMF nevertheless,with Brunnermeier and Sannikov(Brunnermeier&Sannikov,2012),has argued that price stability and financial stability are interlinked Short-term debt financing played an important role in the run-up to the financial crisis,as increases in leverage helped boost growth but also made the economy more susceptible to a downturn.Since the recession,private agents have reduced their debt level while many governments have increased borrowing.This deleveraging process appears to be holding back the recovery,and the Japanese experience suggests that such deleveraging can continue over an extended period”,unless in the long run we are all broken at state level,as history seems now to prove.It is true indeed,as reminded by Lamfalussy(Lamfalussy et al.,2010,pp.7-9),and now widely proved by facts,that prices and the growth-employment objectives,run into each other because it is seldom the case that the pursuit of one is consistent with the pursuit of the second in global economies.
文摘A present monetary theory of the Great Depression has been explained as stemming from Milton Friedman,ignoring the previous Davanzati,a Florentine finding,in the 16th Century,an explanation solution to the increase of prices due to the arrival of Spanish silver from the New World.Designed to counter the Keynesian notion that the Depression resulted from instability theories,characterizing most modern capitalistic economies,Friedmans explanation identified lately the monetary trend as a disordered monetary policy,carried out by erroneous Federal Reserve Board interventions,possible after the Aldrich-Vreeland innovations,introducing Treasury money in the year 1908.More recent works about the Great Depression reconsider the attempts to restore the international gold standard,suppressed on the brink of World War I.We learnt that current views of the Depression,as analyzed in the 1920s by Ralph Hawtrey and Gustav Cassel,while recommending a gold standard reset,reflect that such standard risk deflations,unless the resulting increase in the international monetary demand linked to physical gold,could be satisfied.Although their early warnings of potential disaster became actual and their policy advice was consistently correct,their contributions were ignored and forgotten.The vanishing of their comments was firstly outlined not a long time ago,by Batchelder and Glasner What Ever Happened to Hawtrey and Cassel? (2013)This paper explores the possible reasons for the remarkable historical disregard of the Hawtrey-Cassel monetary explanation of the Great Depression,even by Nobel Prize winner Robert Mundell in his 2000 historical Nobel reconsideration of the monetary 20th century(Mundell,2000).The paper stresses the identical historical conditions surfacing after the Bretton Woods agreements.Robert Triffin and Jacques Rueff comment likely warnings as in the first Great Depression,under the monetary policy illusion and the Central Banks excessive disregard of the basics of the quantitative theory on the long run,mostly ignored.Robert Triffin started to address the problem in March and June of 1959,Italian Banca Nazionale del Lavoro Quarterly Review.The first of these articles(Part One:Diagnosis)explains in the simplest possible terms,the extraordinary success of the nineteenth century system of international gold based convertibility,and the calamitous collapse of the late 1920s attempts to bring it back to life.It may hold for us today an indication of the main efforts facing the similar attempt at reconstructing the past expressed some 64 years later,after the first of August 1914,by Triffin during the 1978 Christmas weekend.To deal with them in simple,commonsense terms would inevitably classify the author as an unrealistic whose views deserve no more than a raising of eyebrows.Jacques Rueff,with his The Monetary Sin of the West,a logical consequence of the Triffin previous notes of the 1960s,went straight to the consequences of the Camp David resolutions of President Nixon who just temporarily asked his Treasury Secretary,John Conally to suspend the gold convertibility.There were two changes in United States(U.S.)government policy toward the monetary role of gold in the last 100 years.The first was in 1933-1934;all holdings of gold were confiscated in March 1933.Then,the U.S.Treasury adopted a parity for the U.S.dollar of$35.00 an ounce at the end of January 1934.Gold production surged,the private demand for gold fell,and the U.S.experienced large increases in foreign demand for U.S.dollar securities.In those years there was a massive flow of gold to the U.S.The second historical change in U.S.gold policy followed the meeting at Camp David on August the 15th 1971,when the U.S.Treasury closed its gold window fearing a run on its gold holdings,declining towards$10 billion.Some U.S.officials sought to diminish the monetary role of gold.The anticipation of some U.S.officials attending Camp David was that the persistent U.S.payments problem would disappear,once foreign currencies had no parities in terms of the U.S.dollar.The prices of these foreign currencies would increase and the U.S.trade surplus would become larger.Instead,many foreign Central Banks became larger buyers of dollarssecurities,which led to a higher price of the U.S.dollar and a U.S.trade structural deficit.The U.S.international investment position morphed from the worlds largest creditor country,to the worlds present day largest debtor.
基金Foundation Project.Capital Medical Development and Research Foundation[2007-1035]。
文摘Purpose:This study aimed to understand the joint standard of blood glucose,blood li-pids,and blood pressure in elderly patients>60 years of age with type 2 diabetes in the Beijing Yongding Road Community.Methods:One hundred ninety-two elderly patients>60 years of age who were diagnosed with type 2 diabetes in Yongding Road Community served as the investigation subjects,under-went standard management,and the dynamic changes in blood glucose,blood lipids,and blood pressure were monitored for 48 months.Results:At the end of the observation period,the standard rates of fasting blood glucose and postprandial blood glucose were 72.55%and 80.00%,respectively,which were increased compared with 55.73%and 56.08%at baseline(P<0.01).The standard rate of HbA1c was 59.81%,which was increased compared with 53.44%at baseline(P>0.05).The standard rates of TG and LDL-C were 76.71%and 60.38%,respectively,which were increased compared with 54.69%and 34.74%at base-line,and the standard rate of HDL-C was 13.64%,which was decreased compared with 40.10%at baseline(P<0.01).The standard rate of BP was 58.33%,which was increased compared with 38.54%at baseline(P<0.01).The optimal control rate of blood glucose for 48 months(the standard times of the total measurement times in 48 months≥75%)was higher;the fasting blood glucose was 52.17%,the 2-h postprandial blood glucose was 60.22%,and the HbA1c was 46.45%.The optimal control rate of blood lipids was lower;LDL-C was 17.49%and HDL-C was 13.59%.The optimal control rate of BP was 9.13%.At the end of the observation period,the levels of fasting blood glucose and postprandial blood glucose were decreased by 0.7 mmol/L and 1.48 mmol/L,respectively,compared with the base-line(P<0.01).The level of HbA1c was decreased by 0.18%compared with the baseline(P<0.05).The levels of LDL-C and HDL-C were decreased by 0.4 mmol/L and 0.23 mmol/L,respectively,compared with the baseline(P<0.01).The levels of SBP and DBP were decreased by 4 mmHg compared with the baseline(P<0.01).At the end of the observation period,the joint standard rate of the three indices of HbA1c,LDL-C,and BP was 24.72%,which was increased compared with 6.25%at baseline(P<0.01).Conclusion:Standardized management of elderly patients with diabetes in the Community can improve the joint standard rate of blood glucose,blood lipids,and blood pressure.The op-timal control rate and joint standard rate are the important indices for evaluating the quality of diabetes management.
基金This work was approved by the UNR IACUC 00687(to CRF)and APSU IACUC 19.023(to CMG)This research was supported by a National Science Foundation grant IOS1355221(to CRF)and a generous gift from Ron Aryel.
文摘Trait specialization often comes at the expense of original trait function,potentially causing evolutionary tradeoffs that may render specialist populations vulnerable to extinction.However,many specialized adaptations evolve repeatedly,suggesting selection favors specialization in specific environments.Some garter snake(Thamnophis)populations possess specialized mutations in voltage-gated sodium channels that allow them to consume Pacific newts(Taricha)defended by a highly potent neurotoxin(tetrodotoxin).These mutations,however,also decrease protein and muscle function,suggesting garter snakes may suffer evolutionary tradeoffs.We measured a key physiological process,standard metabolic rate(SMR),to investigate whether specialized adaptations in toxin-resistant garter snakes affect baseline energy expenditure.In snakes,skeletal muscles influence metabolism and power ventilation,so inefficiencies of sodium channels in these muscles might impact whole-animal energy expenditure.Further,because sodium channels are membrane-bound proteins,inefficiencies of channel kinetics and performance might be exacerbated at suboptimal temperatures.We measured SMR in 2 species,Thamnophis atratus and Thamnophis sirtalis,that independently evolved tetrodotoxin resistance through unique mutations,providing replicate experiments with distinct underlying genetics and potential physiological costs.Despite our expectations,neither resistance phenotype nor sodium channel genotype affected metabolism and resistant snakes did not perform worse under suboptimal body temperature.Instead,T.atratus and T.sirtalis show nearly identical rates of mass-adjusted energy expenditure at both temperatures,despite differing eco-morphologies,life histories,and distant phylogenetic positions.These findings suggest SMR may be a conserved feature of Thamnophis,and that any organismal tradeoffs may be compensated to retain whole-animal function.
