Individual heterogeneity in fitness in a long‐lived herbivore

Heterogeneity in the intrinsic quality and nutritional condition of individuals affects reproductive success and consequently fitness. Black brant (Branta bernicla nigricans) are long‐lived, migratory, specialist herbivores. Long migratory pathways and short summer breeding seasons constrain the time and energy available for reproduction, thus magnifying life‐history trade‐offs. These constraints, combined with long lifespans and trade‐offs between current and future reproductive value, provide a model system to examine the role of individual heterogeneity in driving life‐history strategies and individual heterogeneity in fitness. We used hierarchical Bayesian models to examine reproductive trade‐offs, modeling the relationships between within‐year measures of reproductive energy allocation and among‐year demographic rates of individual females breeding on the Yukon‐Kuskokwim Delta, Alaska, using capture–recapture and reproductive data from 1988 to 2014. We generally found that annual survival tended to be buffered against variation in reproductive investment, while breeding probability varied considerably over the range of clutch size‐laying date combinations. We provide evidence for relationships between breeding probability and clutch size, breeding probability and nest initiation date, and an interaction between clutch size and initiation date. Average lifetime clutch size also had a weak positive relationship with apparent survival probability. Our results support the use of demographic buffering strategies for black brant. These results also indirectly suggest associations among environmental conditions during growth, fitness, and energy allocation, highlighting the effects of early growth conditions on individual heterogeneity, and subsequently, lifetime reproductive investment.     

Evaluation of an enzyme immunoassay for the detection of the mycotoxin tenuazonic acid in sorghum grains and sorghum-based infant food

An enzyme-linked immunosorbent assay (ELISA) for the Alternaria mycotoxin tenuazonic acid (TeA) was evaluated by comparative analysis of naturally contaminated sorghum grains and sorghum-based infant food, using a stable isotope dilution LC-MS assay (SIDA; limit of detection (LOD) 1.0 μg/kg) as the reference method. LODs of the ELISA were 30 μg/kg in sorghum grains and 220 μg/kg in sorghum-based infant cereals. With SIDA, 100% of the samples (n = 28) had been positive for TeA in a concentration range of 6–584 μg/kg (mean 113 μg/kg). The ELISA consistently detected TeA in all naturally contaminated samples at cut-off levels of 30–60 μg/kg (sorghum) and 200–300 μg/kg (infant cereals), as based on corresponding to SIDA values. Although the ELISA was much less sensitive than the SIDA method, it may be useful as a screening method for sorghum and sorghum-based infant foods and can be employed to identify samples containing elevated concentrations of TeA in food, well below the proposed level of concern (500 μg/kg).     

Foraging in honeybees--when does it pay to dance?

Honeybees are unique in that they are the only social insectsthat are known to recruit nest mates using the waggle dance.This waggle dance is used by successful foragers to convey informationabout both the direction and distance to food sources. Nestmates can use this spatial information, increasing their chancesof locating the food source. But how effective is the bees'dance communication? Previous work has shown that dancing doesnot benefit a honeybee colony under all foraging conditionsand that the benefits of dancing are small. We used an individual-basedsimulation model to investigate under which foraging conditionsit pays to dance. We compared the net nectar intake of 3 typesof colonies: 1) colonies that use dance communication; 2) coloniesthat did dance but could not use the dance's spatial information;and 3) colonies that did not dance. Our results show that dancingis beneficial when the probability of independent discoveryof food sources is low. Low independent discovery rates occurwhen patches are very small or very far away. Under these conditions,dancing is beneficial as only a single individual needs to finda patch for the whole colony to benefit. The main benefit ofthe honeybee's dance communication, however, seems to be thatit enables the colony to forage at the most profitable patchesonly, ignoring forage patches that are of low quality. Thus,dancing allows the colony to rapidly exploit high-quality patches,thereby preventing both intra- and interspecific competitorsfrom using that same patch.     

Design and campaign synthesis of piperidine- and thiazole-based histone deacetylase inhibitors

A lead benzamide, 3, was identified as a potent and low molecular weight histone deacetylase (HDAC) inhibitor. Optimization led to 16d, demonstrating an excellent balance of efficacy and non-efficacy properties, along with very desirable in vivo DMPK. The final compounds presented are >1000-fold more potent than the initial screen hit, an improvement in potency which was achieved with a concomitant significant improvement in all the main non-efficacy properties.     

Dimeric thiophosphorus complexes of sodium and zinc: Structural characterization of [(THF)2NaO(S)PPh2]2 and [Zn{S2P(OMe)C6H4OEt-p}2]2

Sodium P,P-diphenylphosphinothioate (2) was prepared by treatment of the free acid, Ph₂P(S)OH (1), with sodium bis(trimethylsilyl)amide and isolated as its THF adduct. The zinc phosphonodithioate complex [Zn{S₂P(OMe)C₆H₄OEt-p}₂]₂ (3) was obtained from ZnCl₂ and the readily accessible sodium salt of the ligand. According to X-ray diffraction studies, both compounds form dimers in the solid state.     

A case of spontaneous acquisition of a human sound by an orangutan

The capacity of nonhuman primates to actively modify the acoustic structure of existing sounds or vocalizations in their repertoire appears limited. Several studies have reported population or community differences in the acoustical structure of nonhuman primate long distance calls and have suggested vocal learning as a mechanism for explaining such variation. In addition, recent studies on great apes have indicated that there are repertoire differences between populations. Some populations have sounds in their repertoire that others have not. These differences have also been suggested to be the result of vocal learning. On yet another level great apes can, after extensive human training, also learn some species atypical vocalizations. Here we show a new aspect of great ape vocal learning by providing data that an orangutan has spontaneously (without any training) acquired a human whistle and can modulate the duration and number of whistles to copy a human model. This might indicate that the learning capacities of great apes in the auditory domain might be more flexible than hitherto assumed. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

DNA damage- and stress-induced apoptosis occurs independently of PIDD

The p53-induced protein with a death domain, PIDD, was identified as a p53 target gene whose main role is to execute apoptosis in a p53-dependent manner. To investigate the physiological role of PIDD in apoptosis, we generated PIDD-deficient mice. Here, we report that, although PIDD expression is inducible upon DNA damage, PIDD-deficient mice undergo apoptosis normally not only in response to DNA damage, but also in response to various p53-independent stress signals and to death receptor (DR) engagement. This indicates that PIDD is not required for DNA damage-, stress-, and DR-induced apoptosis. Also, in the absence of PIDD, both caspase-2 processing and activation occur in response to DNA damage. Our findings demonstrate that PIDD does not play an essential role for all p53-mediated or p53-independent apoptotic pathways. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.