Conclusions: The cognitive decline observed in we


Conclusions: The cognitive decline observed in welders exposed to Mn was associated with a decreased

mI/tCr ratio in the ACC. The depletion of mI in welders may reflect possible glial cell swelling and/or detoxification processes associated with long-term exposure to Mn. (C) 2009 Elsevier Inc. All rights reserved.”
“Objective: This study assessed clinical condition at midterm follow-up after total cavopulmonary connection for a functionally univentricular heart performed on children younger than 5 years.

Methods: Thirty-four Fontan patients (median age 10.4 years, range 6.8-20.7 years, 22 boys, median follow-up 7.8 years, 5.0-17.8 years) underwent electrocardiography, Holter monitoring, bicycle exercise testing, cardiac magnetic resonance imaging, and N-terminal buy Veliparib prohormone brain VX-809 molecular weight natriuretic peptide (NT-pro-BNP) analysis.

Results: Twenty-three patients (68%) were in sinus rhythm. Holter monitoring demonstrated normal mean heart rate,

low maximal heart rate, and no clinically significant arrhythmias or sinus node dysfunction. With maximal bicycle ergometry (n = 19), maximum workload (60% of normal), maximum heart rate (90% of normal), and maximal oxygen uptake (69% of normal) were all significantly lower in the Fontan group than in a control group (P < .001). Variables of submaximal exercise indicated less efficient oxygen uptake during exercise in all Fontan patients. Ejection fraction was lower than in control subjects (59% +/- 13% vs 69% +/- 5%, P < .001). Mean end-diastolic and end-systolic volumes and ventricular mass were higher than in control subjects (P < .001).

Mean NT-pro-BNP levels were increased relative to reference values, but only 8 patients had levels above the upper reference limit.

Conclusion: At midterm buy Evofosfamide follow-up, Fontan patients were in acceptable clinical condition, with preserved global ventricular function, moderately decreased exercise capacity, and NT-pro-BNP levels within reference range. Systemic ventricular mass was elevated, however, suggesting contractility-afterload mismatch. Long-term consequences for ventricular function merit further investigation.”
“In previous work, the outgrowth of axon-like processes by differentiating mouse N2a neuroblastoma cells was shown to be inhibited by exposure to 10 mu M diazinon. In the present work, N2a cells were induced to differentiate for 24 h in the presence and absence of 10 mu M diazinon and 20% (v/v) conditioned medium derived from differentiating rat C6 glioma cells. Cells were then stained or lysed for morphological and biochemical analyses, respectively. The data showed that co-treatment with conditioned medium prevented the neurite inhibitory effect of diazinon.

The duplex real-time RT-PCR was capable of specifically detecting

The duplex real-time RT-PCR was capable of specifically detecting different subgroups of wild-type CSFV and different strains of NAgenotype PRRSV, whereas a number of non-CSFV/PRRSV porcine viruses and bovine pestivirus were tested negative. Out Of 155 field samples, 16 were tested positive for CSFV, 73 were positive for PRRSV, and 13 were co-infected with the two Viruses. These results were 99.4% in agreement with those using conventional RT-PCRs. Therefore, the assay provides sensitive and simultaneous detection and differentiation of CSFV and PRRSV. (c) 2008 Elsevier B.V. All rights

“Spontaneously depressed flinders sensitive line (FSL) rats showed a reduced expression of mGlu2/3 metabotropic glutamate receptors in the hippocampus, as compared to “”non-depressed”" flinders resistant line (FRL) rats. No

changes in mGlu2/3 receptor protein IPI-549 levels were found in other brain regions, including the amygdala, hypothalamus, and cerebral cortex. Biochemical analysis of receptor signalling supported the reduction of mGlu2/3 receptors in the hippocampus PLX4032 of FSL rats. Accordingly, the selective mGlu2/3 receptor agonist, LY379268 (1 mu M) reduced forskolin-stimulated cAMP formation by 56% and 32% in hippocampal slices from FRL and FSL rats, respectively. In addition, LY379268 enhanced 3,5-dihydroxyphenylglycine-stimulated inositol phospholipid hydrolysis from 65% to 215% in hippocampal slices from FRL rats, whereas it was inactive in slices from FRL rats. We also examined the behavioural response of FSL rats to systemic injection Blebbistatin solubility dmso of LY379268 (0.5 mg/kg,

i.p., once a day for 1-21 days) by measuring the immobility time in the forced swim test, which is known to be increased in these rats. LY379268 was administered alone or combined with the classical antidepressant, chlorimipramine (10 mg/kg, i.p.). LY379268 alone had no effect at any of the selected time-points, whereas chlorimipramine alone reduced the immobility time only after 21 days of treatment. In contrast, when combined with LY379268, chlorimipramine reduced the immobility time during the first 14 days of treatment. These data support the view that rnGlu2/3 receptors might be involved in the pathophysiology of depressive disorders, and that pharmacological activation of these receptors may shorten the latency of antidepressant medication. (C) 2008 Elsevier Ltd. All rights reserved.”
“Reverse transcription loop-mediated isothermal amplification (RT-LAMP) is a unique gene amplification method that can be completed within 45 min at 63 degrees C. In this study, RT-LAMP was used to develop a rapid and sensitive laboratory diagnostic system for the H9 subtype of avian influenza virus (AIV).

“Viruses in the Ebolavirus and Marburgvirus genera (family

“Viruses in the Ebolavirus and Marburgvirus genera (family Filoviridae) have been associated with large outbreaks of hemorrhagic fever in human and nonhuman primates. The first documented cases occurred in primates over 45 years

ago, but the amount of virus genetic diversity detected within bat populations, which have recently been identified as potential reservoir hosts, suggests check details that the filoviruses are much older. Here, detailed Bayesian coalescent phylogenetic analyses are performed on 97 whole-genome sequences, 55 of which are newly reported, to comprehensively examine molecular evolutionary rates and estimate dates of common ancestry for viruses within the family Filoviridae. Molecular evolutionary rates for viruses belonging to different species range from 0.46 x 10(-4) nucleotide substitutions/site/year for Sudan ebolavirus to 8.21 x 10(-4) nucleotide substitutions/ site/year for Reston ebolavirus. Most recent common ancestry can be traced back only within the last 50 years for Reston ebolavirus and Zaire ebolavirus species and suggests that viruses within these species may have undergone recent genetic bottlenecks. Viruses within Marburg marburgvirus and Sudan ebolavirus species can be traced back further and share most recent common ancestors approximately 700 and 850 years before the present, respectively. Examination of the whole family suggests that members of the Filoviridae, PRT062607 purchase including

the recently described Lloviu virus, shared a

most recent common ancestor approximately 10,000 years ago. These data will be valuable for understanding the evolution of filoviruses in the context of natural history as new reservoir hosts are identified and, further, for determining mechanisms of emergence, pathogenicity, and the ongoing threat to public health.”
“The mitotic spindle faithfully separates the genetic material, and has been reverently observed for well over a century. Across eukaryotes, while the Evofosfamide concentration mechanisms for moving chromosomes seem quite conserved, mechanisms for assembling the spindle often seem distinct. Two major pathways for spindle assembly are known, one based on centrosomes and the other based on chromatin, and these pathways are usually considered to be fundamentally different. We review observations of spindle assembly in animals, fungi, and plants, and argue that microtubule assembly at a particular location, centrosomes, or chromatin, reflects contingent, cell-type specific factors, rather than reflecting a fundamental distinction in the process of spindle building. We hypothesize that the essential process for spindle assembly is the motor-driven organization of microtubules that accumulate in the form of dense bundles at or near the chromosomes.”
“Little is known concerning immunodominance within the CD4 T-cell response to viral infections and its persistence into long-term memory.

6 and

0 7 mg/kg, s c ) or ethanol (0 5 g/kg, i p ) improv

6 and

0.7 mg/kg, s.c.) or ethanol (0.5 g/kg, i.p.) improved WIN-induced memory impairment, suggesting a cross state-dependent memory retrieval between the drugs. Pre-test intra-CA1 microinjection of nicotine (1 and 2 mu g/mouse) before systemic administration of an ineffective SP600125 solubility dmso dose of nicotine (0.5 mg/kg, s.c.) or ethanol (0.25 g/kg) significantly reversed WIN-induced memory impairment. Pre-test intra-CA1 microinjection of mecamylamine (1 and 3 mu g/mouse) inhibited cross state-dependent memory between WIN and nicotine or ethanol. Moreover, pre-test intra-MS microinjection of nicotine (1 and 2 mu g/mouse) in combination with systemic administration of a lower dose of nicotine (0.5 mg/kg), but not ethanol (0.25 g/kg), improved memory impairment induced by pre-training administration of WIN. On the other hand, in the animals that received pre-training WIN and pretest systemic administration of nicotine (0.7 mg/kg), but not ethanol (0.5 g/kg), pre-test intra-MS microinjection of mecamylamine (1-5 mu g/mouse) inhibited

selleck products WIN-nicotine state-dependent memory retrieval. It should be noted that pre-test intra-CA1 or intra-MS microinjection of nicotine or mecamylamine by itself had no effect on memory retrieval and also could not reverse memory impairment induced by pre-training administration of WIN. It can be concluded that WIN and nicotine or WIN and ethanol can induce state-dependent memory retrieval. In addition, our results showed that a cross-state dependency between these drugs may be mediated through a cholinergic nicotinic mechanism. (C) 2013 IBRO. Published by Elsevier Ltd. All rights reserved.”
“Reticulospinal (RS) neurons are critical for initiation of locomotor behavior, and following spinal cord injury (SCI) in the lamprey, the axons of these neurons regenerate and restore locomotor behavior within a few weeks. For lamprey RS neurons learn more in culture, experimental induction of calcium influx, either in the growth cone or cell body, is inhibitory for neurite outgrowth. Following SCI, these neurons partially downregulate calcium channel expression, which would be expected to reduce calcium influx and possibly provide supportive

conditions for axonal regeneration. In the present study, it was tested whether activation of second messenger signaling pathways stimulates neurite outgrowth of lamprey RS neurons without altering their electrical properties (e.g. spike broadening) so as to possibly increase calcium influx and compromise axonal growth. First, activation of cAMP pathways with forskolin or dbcAMP stimulated neurite outgrowth of RS neurons in culture in a PKA-dependent manner, while activation of cGMP signaling pathways with dbcGMP inhibited outgrowth. Second, neurophysiological recordings from uninjured RS neurons in isolated lamprey brain spinal cord preparations indicated that dbcAMP or dbcGMP did not significantly affect any of the measured electrical properties.


In patients, V(root) was 6 4% +/- 4 8% of the in


In patients, V(root) was 6.4% +/- 4.8% of the intraaortic balloon volume during 1:1 assistance and 10.0% +/- 5.0% during 1:2 assistance. In vitro and with an artificial heart simulating the native heart, V(cor) was smaller, 3.7% and 3.8%, respectively. The distribution of V(tip) in vitro varied, with less volume displaced toward the arch and coronary branches and more volume stored in the compliant aortic wall when the artificial heart was not operating.

Conclusion: The blood volume displaced toward the coronary circulation as the result of intraaortic balloon inflation is a small percentage of the nominal intraaortic balloon volume. Although small, this percentage is still a significant fraction of baseline coronary flow. (J Thorac Cardiovasc Surg 2010;140:110-6)”
“The aim of this research was to prepare a multifunctional system of technetium-99m-labelled Selleck Wortmannin gold nanoparticles conjugated to HYNIC-GGC/mannose and to evaluate its biological behaviour as a potential radiopharmaceutical

for sentinel lymph node detection (SLND).

Methods: Hydrazinonicotinamide-Gly-Gly-Cys-NH2 (HYNIC-GGC) peptide and a thiol-triazole-mannose derivative were synthesized, characterized and conjugated to gold nanoparticles (AuNP, 20 nm) to prepare a multifunctional system of HYNIC-GGC-AuNP-mannose by means of spontaneous MDV3100 clinical trial reaction of the thiol (Cys) present in HYNIC-GGC sequence and in the thiol-mannose derivative. The nanoconjugate was characterized by transmission electron microscopy (TEM), IR, UV-Vis, Raman, fluorescence and X-ray photoelectron spectroscopy (XPS). Technetium-99m labelling was carried out using EDDA/tricine as coligands and SnCl2 as reducing agent with further size-exclusion chromatography

purification. Radiochemical purity was determined by size-exclusion HPLC and ITLC-SG analyses. In vitro binding studies were carried out in rat liver homogenized tissue (mannose-receptor positive tissue). Biodistribution studies were accomplished in Wistar rats and images obtained using Elafibranor a micro-SPECT/CT system.

Results: TEM and spectroscopy techniques demonstrated that AuNPs were functionalized with HYNIC-GGC-NH2 and thiol-mannose through interactions with thiol groups and the N-terminal amine of cysteine. Radio-chromatograms showed radiochemical purity higher than 95%. Tc-99m-EDDA/HYNIC-GGC-AuNP-mannose (Tc-99m-AuNP-mannose) showed specific recognition for mannose receptors in rat liver tissue. After subcutaneous administration of Tc-99m-AuNP-mannose in rats (footpad), radioactivity levels in the popliteal and inguinal lymph nodes revealed that 99% of the activity was extracted by the first lymph node (popliteal extraction). Biodistribution studies and in vivo micro-SPECT/CT images in Wistar rats showed an evident lymph node uptake (11.58 +/- 1.98 %ID at 1 h) which was retained during 24 h with minimal kidney accumulation (0.98 +/- 0.10 %ID) and negligible uptake in all other tissues.

“OBJECTIVE: Although endoscopic perforation of the septum

“OBJECTIVE: Although endoscopic perforation of the septum pellucidum in obstruction of the foramen of Monro is well known, detailed reports on endoscopic septostomy, including surgical technique and results are lacking in the literature.

METHODS: All intracranial endoscopic procedures performed between February 1993 and March 2008 were find more evaluated. All patients with blockage of the foramen of Monro that was treated with endoscopic septostomy were analyzed and prospectively followed. Particular attention was given to indications, approach, surgical technique,

complications, and results.

RESULTS: Thirty-two endoscopic septostomies were performed in 30 patients (17 male patients, 13 female patients; mean age, 31 years; age range, 4 months-68 years). Cerebrospinal fluid circulation was obstructed by tumor (16 cases), multiloculated cystic hydrocephalus https://www.selleckchem.com/products/oligomycin-a.html (8 cases, including 2 revisions), septum pellucidum cysts (3 cases), membranous or inflammatory isolated lateral

ventricles (3 cases), and giant aneurysms (2 cases). Simultaneously with septostomy, 13 endoscopic tumor procedures, 9 endoscopic third ventriculostomies, and 9 other endoscopic procedures were performed. The mean surgical time was 80 minutes (range, 45-135 minutes). There were 4 asymptomatic complications (13%), 5 transient complications (16%), and no permanent complications.

Postoperatively, 26 patients (87%) improved. Two revisions had to be performed. The mean follow-up period was 16 months (range, 1-93 months).

CONCLUSION: On the basis of the results, long-standing cerebrospinal fluid circulation restoration can be achieved with endoscopic septostomy. Endoscopic septostomy is a safe and reliable endoscopic technique that should be considered more frequently for the restoration of cerebrospinal fluid circulation in the treatment of blockage of the foramen of Monro.”
“OBJECTIVE: An index of cerebrospinal compensatory reserve (RAP) has been introduced as a potential descriptor of neurological deterioration after head trauma. It is numerically computed as a linear correlation coefficient between the mean Galactokinase intracranial pressure and the pulse amplitude of the pressure waveform. We explore how RAP varies with different forms of physiological or nonphysiological intracranial volume loads in adult hydrocephalus, with and without a functioning cerebrospinal fluid (CSF) shunt.

METHODS: A database of intracranial pressure recordings during CSF infusion studies and overnight monitoring in hydrocephalic patients was reviewed for clinical comparison of homogeneous subgroups of patients with hypothetical differences of pressure-volume compensatory reserve.

These results confirm a pattern of subtle and inconsistent long-t

These results confirm a pattern of subtle and inconsistent long-term effects of repeated daily exposure to concentrations of toluene vapor of 1000 ppm and below, in contrast to robust and reliable effects of acute inhalation of the solvent at concentrations

above 1000 ppm. Published by Elsevier Inc.”
“Across many domains of cognition, information processing is more effective when it has been performed recently than when it has not. This effect-termed repetition priming-is ubiquitous; however, its causes are not well understood. Here, I draw attention to the concept of antipriming and argue that it is crucial for understanding priming. Antipriming is a measurable impairment in processing information owing to recent processing of other information when the representations of information overlap and compete. GW786034 in vitro Strengthening one representation after its usage causes priming for that item but also antipriming for some other, non-repeated items.

Recent evidence demonstrates priming and antipriming within visual object identification systems. These findings might reflect a form of maintenance relearning of superimposed knowledge representations.”
“Purpose: Incontinence after radical prostatectomy Paclitaxel clinical trial is common yet poorly defined in the current literature. We aimed to accurately IPI145 mouse characterize incontinence after robot-assisted radical prostatectomy to achieve improved preoperative patient counseling.

Materials and Methods: After receiving institutional review board approval we performed a cross-sectional

survey of the first 600 patients with prostate cancer who underwent robot-assisted radical prostatectomy at our institution. The International Consultation on Incontinence Modular Questionnaire-Lower Urinary Tract Symptoms Quality of Life and Urinary Incontinence Short Form were used to evaluate incontinence and quality of life after robot-assisted radical prostatectomy. Surveys were mailed by a third party. Data were analyzed on the prevalence of incontinence after robot-assisted radical prostatectomy. More specifically we characterized in detail the nature of incontinence and its effect on quality of life.

Results: The response rate was 68% (408 of 600 participants). Response time since surgery was 2.5 months to 4 years. Overall incontinence bother scores and ratings of life interference were quite low. Patients reported that most incontinence occurred during physical activity but 35% reported interference with sleep. Of the patients 31% experienced some anxiety due to urinary difficulties and 51% had to occasionally change clothes due to leakage. Patients did not report much interference with traveling, visiting friends or family and family life.

We found that primary astrocytes express different sterol hydroxy

We found that primary astrocytes express different sterol hydroxylases and are able to uptake exogenous 27-hydroxycholesterol. We found that both microglia and astrocytes express preferentially Lxr beta. However, despite this similarity, we observed cell-specific responsiveness of known and novel (including Cyp27a1) target genes to LXR activation. The increase of mRNA and protein levels in treated astrocytes is paralleled by transactivation of the proximal Cyp27a1 promoter in transfected astrocytes. We

suggest that the astrocyte-restricted up-regulation of Cyp27a1 may be ascribable to differential expression of transcriptional co-activators. Given the role of astrocytes in maintaining brain homeostasis, we hypothesize that impairment of CYP27 activity in these cells may alter critical features HDAC inhibitor of the astrocytes, from the handling and delivery of cholesterol to neurons to the release of signaling molecules. (C) 2009 IBRO. Published by Elsevier Ltd. All rights RG7112 nmr reserved.”
“Purpose: We evaluated whether high voiding pressures in patients with posterior urethral valves are associated with reduced kidney function.

Materials and Methods: A total of 25 children younger than 12 months with posterior urethral valves underwent urodynamic

evaluation within 15 days of valve ablation between 1994 and 2007. Six patients underwent primary urodynamics before and 19 after valve ablation. A total of 17 patients underwent repeat studies after I month and 1 year. Maximum detrusor pressures during voiding and cystometric bladder capacity were compared with kidney function tests. Maximum detrusor pressures during voiding was compared with a control group and data from other studies of male infants.

Results: At presentation median cystometric bladder capacity was 22 ml (range 5 to 125) and maximum voiding pressure was 112 cm H(2)O (40 to 331). There was no statistical

difference in bladder capacity and voiding selleck screening library pressures before and after valve ablation. Also, patients with and without vesicoureteral reflux had similar bladder capacities and voiding pressures. There was no association between primary voiding pressures and serum creatinine levels or kidney split function during the first year of life. Primary voiding pressures were about the same as in a control group and in previous studies of males who were healthy, who had reflux or whose status was post-pyelonephritis. Voiding pressures had decreased and bladder capacity had increased significantly at 1-year followup.

Conclusions: Voiding pressures in infants with posterior urethral valves are as high as but not higher than other male infants. High voiding pressures postnatally are not associated with reduced kidney function.”
“Ubiquitin proteasome system (UPS) and autophagy lysosome pathway (ALP) are the two most important routes for degradation of aggregated/misfolded proteins.

(c) 2013 Elsevier Inc All rights reserved “
“A strong posit

(c) 2013 Elsevier Inc. All rights reserved.”
“A strong positive association between depression and alcoholism is evident in epidemiological studies. Curiously, the incidence of smoking (nicotine intake) Verteporfin cell line is also very high among depressed individuals. Because neuronal nicotinic receptors have been implicated in mood regulation as well as in reinforcing effects of alcohol, it was of interest to determine whether inherent changes in these

receptors may be manifested in an animal model that expresses both depressive-like characteristics and high alcohol intake. Thus, Fawn-Hooded (FH) rats along with their control ACI rats were used to measure the density of the high affinity nicotinic receptor in discrete brain regions. Furthermore, the effects of acute and chronic nicotine on depressive-like characteristics of FH rats were also evaluated. Measurements of [(3)H]cytisine binding (selective for alpha 4 find more beta 2 nicotinic receptor subtype) revealed a reduction in these receptors only in the striatum of FH rats, a result very similar to that observed in selectively-bred alcohol-preferring (P) rats. Administration of nicotine acutely (0.4 mg/kg, sc) resulted in a significant reduction of immobility in the forced swim test (FST) in FH rats only, implying an antidepressant-like effect of nicotine. Another group of FH rats were administered 0.4 mg/kg nicotine (daily, sc) for 14 days and their behavior in the FST was evaluated 22-24 h

after the click here last injection. In this case, nicotine also had a significant antidepressant-like effect in FH rats suggesting no tolerance to nicotine had occurred. The effects of nicotine on FST behavior are very similar to those observed in

Flinders Sensitive Line rats, a putative animal model of depression. Together, these findings provide additional evidence for antidepressant-like effects of nicotine and strengthen the postulated association between striatal nicotinic receptors and high alcohol intake. Thus. nicotinic receptors could be suitable targets for the development of novel pharmacotherapy for treatment of depression and possibly alcoholism. (C) 2008 Elsevier Inc. All rights reserved.”
“In this study we examined asymmetric semantic activation patterns as people listened to conversations and narratives that promoted causal inferences. Based on the hypothesis that understanding the unique features of conversational input may benefit from or require a modified pattern of conceptual activation during conversation, we compared semantic priming in both hemispheres for inferences embedded in conversations and in narratives. Participants named inference-related target words or unrelated words presented to the left visual field-right hemisphere (lvf-RH) or to the right visual field-left hemisphere (rvf-LH) at critical coherence points that required an inference in order to correctly understand an utterance in the context of the conversation or narrative.

(C) 2008 Elsevier Ltd All rights reserved “
“According to p

(C) 2008 Elsevier Ltd. All rights reserved.”
“According to previous studies, ultrasound can be perceived through bone conduction and ultrasound amplitude modulated by different speech sounds can be discriminated by some profoundly deaf subjects as well as the normal-hearing. These findings suggest the usefulness of development of a bone-conducted ultrasonic hearing aid (BCUHA) for profoundly deaf subjects. In this study, with a view to developing a frequency modulation system in a BCUHA, the capability to discriminate the frequency of sinusoidal bone-conducted ultrasound (BCU) was evaluated by

measuring mismatch fields Selleckchem RepSox (MMF). We compared MMFs between BCU (standard stimuli were 30 kHz, and deviant stimuli were 27 and 33 kHz) and air-conducted audible sound (ACAS; standard stimuli were 1 kHz, and deviant stimuli were 900 and 1100 Hz). MMFs were observed in all subjects for ACAS, however, not observed in a few subjects for BCU. Further, the mean peak amplitudes of

MMF for BCU were significantly less than those for ACAS. These findings indicate that the discrimination capability of frequency of sinusoidal BCU is inferior to that of ACAS. It was also demonstrated that normal hearing could to some extent discriminate differences in frequency in sinusoidal BCU. The results indicate a possibility of transmission system Copanlisib for language information making use of frequency discrimination. (C) 2008 Elsevier Ireland Ltd. All rights reserved.”
“This is the second in a series of three papers devoted to energy flow and entropy changes in chemical and biological processes, and to their relations to the thermodynamics of computation. In the first

paper of the series, it was shown that a general-form dimensional argument from the second law of thermodynamics captures a number of scaling relations governing growth and development across many domains XAV-939 in vivo of life. It was also argued that models of physiology based on reversible transformations provide sensible approximations within which the second-law scaling is realized. This paper provides a formal basis for decomposing general cyclic, fixed-temperature chemical reactions, in terms of the chemical equivalent of Carnot’s cycle for heat engines. It is shown that the second law relates the minimal chemical work required to perform a cycle to the Kullback-Leibler divergence produced in its chemical output ensemble from that of a Gibbs equilibrium. Reversible models of physiology are used to create reversible models of natural selection, which relate metabolic energy requirements to information gain under optimal conditions. When dissipation is added to models of selection, the second-law constraint is generalized to a relation between metabolic work and the combined energies of growth and maintenance. (C) 2008 Elsevier Ltd. All rights reserved.