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Primates and Philosophers : How Morality Evolved
\"Can virtuous behavior be explained by nature, and not by human rational choice? In Primates and philosophers, renowned primatologist Frans de Waal explores the biological foundations of one of humanity's most cherished traits: morality. Drawing on Darwin, recent scientific advances, and his extensive research of primate behavior, de Waal argues that modern-day evolutionary biology incorrectly reinforces our habit of labeling ethical behavior as humane and the less civilized as animalistic. His compelling account of how human morality evolved out of mammalian society will fascinate anyone who has ever wondered about the origins and reach of human goodness.\"--Page 4 of cover.
Book
Revisiting the evolution of ecological specialization, with emphasis on insect-plant interactions
Ecological specialization is a fundamental and well-studied concept, yet its great reach and complexity limit current understanding in important ways. More than 20 years after the publication of D. J. Futuyma and G. Moreno's oft-cited, major review of the topic, we synthesize new developments in the evolution of ecological specialization. Using insect-plant interactions as a model, we focus on important developments in four critical areas: genetic architecture, behavior, interaction complexity, and macroevolution. We find that theory based on simple genetic trade-offs in host use is being replaced by more subtle and complex pictures of genetic architecture, and multitrophic interactions have risen as a necessary framework for understanding specialization. A wealth of phylogenetic data has made possible a more detailed consideration of the macroevolutionary dimension of specialization, revealing (among other things) bidirectionality in transitions between generalist and specialist lineages. Technological advances, including genomic sequencing and analytical techniques at the community level, raise the possibility that the next decade will see research on specialization spanning multiple levels of biological organization in non-model organisms, from genes to populations to networks of interactions in natural communities. Finally, we offer a set of research questions that we find to be particularly pressing and fruitful for future research on ecological specialization.
Journal Article
The lives of animals
The author of these lectures uses fiction to present a discussion of animal rights in all their complexity. The story draws us into Elizabeth Costello's own sense of mortality, her compassion for animals and her alienation from humans.
Book
A systematic review and meta-analysis of early goal-directed therapy for septic shock: the ARISE, ProCESS and ProMISe Investigators
Purpose
To determine whether early goal-directed therapy (EGDT) reduces mortality compared with other resuscitation strategies for patients presenting to the emergency department (ED) with septic shock.
Methods
Using a search strategy of PubMed, EmBase and CENTRAL, we selected all relevant randomised clinical trials published from January 2000 to January 2015. We translated non-English papers and contacted authors as necessary. Our primary analysis generated a pooled odds ratio (OR) from a fixed-effect model. Sensitivity analyses explored the effect of including non-ED studies, adjusting for study quality, and conducting a random-effects model. Secondary outcomes included organ support and hospital and ICU length of stay.
Results
From 2395 initially eligible abstracts, five randomised clinical trials (
n
= 4735 patients) met all criteria and generally scored high for quality except for lack of blinding. There was no effect on the primary mortality outcome (EGDT: 23.2 % [495/2134] versus control: 22.4 % [582/2601]; pooled OR 1.01 [95 % CI 0.88–1.16],
P
= 0.9, with heterogeneity [
I
2
= 57 %;
P
= 0.055]). The pooled estimate of 90-day mortality from the three recent multicentre studies (
n
= 4063) also showed no difference [pooled OR 0.99 (95 % CI 0.86–1.15),
P
= 0.93] with no heterogeneity (
I
2
= 0.0 %;
P
= 0.97). EGDT increased vasopressor use (OR 1.25 [95 % CI 1.10–1.41];
P
< 0.001) and ICU admission [OR 2.19 (95 % CI 1.82–2.65);
P
< 0.001]. Including six non-ED randomised trials increased heterogeneity (
I
2
= 71 %;
P
< 0.001) but did not change overall results [pooled OR 0.94 (95 % CI 0.82 to 1.07);
P
= 0.33].
Conclusion
EGDT is not superior to usual care for ED patients with septic shock but is associated with increased utilisation of ICU resources.
Journal Article
Heart rate reduction with esmolol is associated with improved arterial elastance in patients with septic shock: a prospective observational study
Purpose
Ventricular–arterial (V–A) decoupling decreases myocardial efficiency and is exacerbated by tachycardia that increases static arterial elastance (Ea). We thus investigated the effects of heart rate (HR) reduction on Ea in septic shock patients using the beta-blocker esmolol. We hypothesized that esmolol improves Ea by positively affecting the tone of arterial vessels and their responsiveness to HR-related changes in stroke volume (SV).
Methods
After at least 24 h of hemodynamic optimization, 45 septic shock patients, with an HR ≥95 bpm and requiring norepinephrine to maintain mean arterial pressure (MAP) ≥65 mmHg, received a titrated esmolol infusion to maintain HR between 80 and 94 bpm. Ea was calculated as MAP/SV. All measurements, including data from right heart catheterization, echocardiography, arterial waveform analysis, and norepinephrine requirements, were obtained at baseline and at 4 h after commencing esmolol.
Results
Esmolol reduced HR in all patients and this was associated with a decrease in Ea (2.19 ± 0.77 vs. 1.72 ± 0.52 mmHg l
−1
), arterial d
P
/d
t
max
(1.08 ± 0.32 vs. 0.89 ± 0.29 mmHg ms
−1
), and a parallel increase in SV (48 ± 14 vs. 59 ± 18 ml), all
p
< 0.05. Cardiac output and ejection fraction remained unchanged, whereas norepinephrine requirements were reduced (0.7 ± 0.7 to 0.58 ± 0.5 µg kg
−1
min
−1
,
p
< 0.05).
Conclusions
HR reduction with esmolol effectively improved Ea while allowing adequate systemic perfusion in patients with severe septic shock who remained tachycardic despite standard volume resuscitation. As Ea is a major determinant of V–A coupling, its reduction may contribute to improving cardiovascular efficiency in septic shock.
Journal Article
Host specificity of Lepidoptera in tropical and temperate forests
For numerous taxa, species richness is much higher in tropical than in temperate zone habitats. A major challenge in community ecology and evolutionary biogeography is to reveal the mechanisms underlying these differences. For herbivorous insects, one such mechanism leading to an increased number of species in a given locale could be increased ecological specialization, resulting in a greater proportion of insect species occupying narrow niches within a community. We tested this hypothesis by comparing host specialization in larval Lepidoptera (moths and butterflies) at eight different New World forest sites ranging in latitude from 15° S to 55° N. Here we show that larval diets of tropical Lepidoptera are more specialized than those of their temperate forest counterparts: tropical species on average feed on fewer plant species, genera and families than do temperate caterpillars. This result holds true whether calculated per lepidopteran family or for a caterpillar assemblage as a whole. As a result, there is greater turnover in caterpillar species composition (greater β diversity) between tree species in tropical faunas than in temperate faunas. We suggest that greater specialization in tropical faunas is the result of differences in trophic interactions; for example, there are more distinct plant secondary chemical profiles from one tree species to the next in tropical forests than in temperate forests as well as more diverse and chronic pressures from natural enemy communities.
Journal Article
Levosimendan for the Prevention of Acute Organ Dysfunction in Sepsis
In a randomized trial, over 500 patients with sepsis received levosimendan or placebo in addition to usual care. Levosimendan did not result in a lower likelihood of organ dysfunction or lower mortality.
Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection
1
and is a leading cause of death worldwide. Septic shock is the most severe form of the condition and results in circulatory and metabolic abnormalities.
2
Persisting hypotension despite adequate fluid resuscitation is due to a combination of profound vasodilatation, vascular hyporeactivity to catecholamines, and myocardial depression.
3
Although catecholamines are the recommended first-line therapy for septic shock,
4
high doses of administered catecholamines and high levels of circulating catecholamines are associated with poor outcomes and severe side effects, including myocardial injury and peripheral ischemia.
5
–
7
Levosimendan is . . .
Journal Article
BMI and waist circumference as predictors of lifetime colon cancer risk in Framingham Study adults
BACKGROUND:
It is unclear whether the increased risk of colon cancer associated with obesity differs for men and women, by distribution of body fat, or by location of the tumor. The primary goal of this study was to address these questions.
METHODS:
Eligible subjects from the Framingham Study cohort were classified according to body mass index (BMI) and waist size during two age periods: 30–54 y (
n
=3764) and 55–79 y (
n
=3802). All eligible men and women were cancer-free at baseline and had complete information on the following potential confounders: age, sex, education, height, activity, smoking, and alcohol. There were 157 incident lifetime cases of colon cancer among those followed beginning at 30–54 y of age and 149 lifetime cases among those whose follow up began at 55–79 y. Subjects were stratified further by gender, activity, and tumor location. The Cox Proportional Hazards Models were used to adjust for possible confounding by the above-described factors.
RESULTS:
A BMI ≥30 led to a 50% increased risk (95% CI: 0.92–2.5) of colon cancer among middle-aged (30–54 y) and a 2.4-fold increased risk (95% CI: 1.5–3.9) among older (55–79 y) adults. The BMI effect was stronger for men than for women and for cases occurring in the proximal colon. These adverse effects generally diminished when waist was added to the multivariable models. A larger waist size (≥99.1 cm (39 in) and 101.6 cm (40 in) for women and men, respectively) was associated with a two-fold increased risk of colon cancer; this risk increased linearly with increasing waist size and was evident for both proximal and distal colon cancer. There was no attenuation of these effects when BMI was added to the multivariable models. A larger waist had a particularly adverse effect among sedentary subjects (relative risk (RR)=4.4 for middle-aged adults; RR=3.0 for older adults).
CONCLUSION:
These findings suggest that waist circumference is a stronger predictor of colon cancer risk than is BMI, and that central obesity is responsible for an increased risk of cancer of both the proximal and distal colon.
Journal Article
Critical evaluation of the use of laser diffraction for particle-size distribution analysis
Determination of soil particle-size distribution (PSD) by sieving, hydrometer, and pipette methods as well as by laser diffraction (LD) suffers from inherent flaws, mainly due to the difficulty in defining the size of irregularly shaped particles. Therefore these methods yield only estimates of PSD. The objective of this study was to determine whether a functional relationship exists between the PSDs obtained by the combined sieve-pipette method and those obtained by LD. Samples from 42 California soils were analyzed. For the LD measurements a Beckman-Coulter LS-230 apparatus with a 750-nm laser beam that measures particles in the range of 0.04 to 2000 micrometer was used, employing the Mie theory for the PSD calculations. Values of 1.5 and 0.2 for the real part and the imaginary term of the refractive index (RI), respectively, gave satisfactory results for the optical model calculations. Volume percentage of the clay-size fraction obtained by LD was generally lower than mass percentage of the clay fraction derived by the pipette method. The opposite trend was noted for the silt-size fraction. Coefficients of determination for the regression equations for the clay, silt, and sand fractions determined by the two methods were 0.702, 0.689, and 0.821, respectively. Good agreement between measured and calculated LD values for one size class was accompanied by poor agreement between measured and calculated values for the other. The LD method provides a continuous PSD curve, which enables a detailed data analysis and a flexible application of different particle-size dependent classification systems.
Journal Article
Hook length of the bacterial flagellum is optimized for maximal stability of the flagellar bundle
Most bacteria swim in liquid environments by rotating one or several flagella. The long external filament of the flagellum is connected to a membrane-embedded basal body by a flexible universal joint, the hook, which allows the transmission of motor torque to the filament. The length of the hook is controlled on a nanometer scale by a sophisticated molecular ruler mechanism. However, why its length is stringently controlled has remained elusive. We engineered and studied a diverse set of hook-length variants of Salmonella enterica. Measurements of plate-assay motility, single-cell swimming speed, and directional persistence in quasi-2D and population-averaged swimming speed and body angular velocity in 3D revealed that the motility performance is optimal around the wild-type hook length. We conclude that too-short hooks may be too stiff to function as a junction and too-long hooks may buckle and create instability in the flagellar bundle. Accordingly, peritrichously flagellated bacteria move most efficiently as the distance travelled per body rotation is maximal and body wobbling is minimized. Thus, our results suggest that the molecular ruler mechanism evolved to control flagellar hook growth to the optimal length consistent with efficient bundle formation. The hook-length control mechanism is therefore a prime example of how bacteria evolved elegant but robust mechanisms to maximize their fitness under specific environmental constraints.
Journal Article