Spotting the Top Male: Sexual Selection in a Lek-Mating Paper Wasp, Polistes dominulus.

Acquiring mates is a problem ubiquitous in the animal kingdom. Males typically face the brunt of the burden by bearing the elaborate weaponry and ornamentation required to compete for and attract females. Despite prolific interest in understanding the dynamics of male-male competition and female choice, many questions remain. In particular, there is little understanding of how sexual selection operates in systems lacking obviously costly ornamentation, or what drives female choice in systems in which males provide no tangible resources. Polistes paper wasps serve as a uniquely-suited model organism with which to address these questions: they epitomize intense competition as they have lek-based mating systems; females are genetically monogamous, suggesting strong female choosiness; and females hibernate between mating and producing offspring, making male ejaculate quality an important factor for female fitness. Finally, male paper wasps are unique among lekking organisms in that they do not appear to possess the obviously costly ornamentation typical of lekking males. Despite these interesting facets of paper wasp reproductive biology, it remains poorly studied. Here, I examine multiple aspects of the mating system of Polistes dominulus paper wasps, with the following objectives: (1) to identify sexually selected signals, (2) to determine whether identified signals advertise quality information, and (3) to determine how females benefit from choice in a lekking system. I show that while chemical information is unrelated to reproductive success, male morphology functions as condition dependent sexually selected quality signals: males use dorsal abdominal spots in both inter- and intra-sexual competition, and larval diet influences the development of these spots. Further, female choice for attractive spots results in direct benefits to females, with females whose mates advertise high quality surviving hibernation longer than females whose mates advertise low quality. Overall, these results demonstrate that male ornaments are important mediators of mating dynamics in Polistes dominulus. Moreover, they show that females can gain direct benefits in non-economic mating systems, providing an alternative hypothesis to “good genes” models of female choice on leks. This work builds a foundation necessary for paper wasps to become model organisms for studying sexual selection and lekking dynamics.Ph.D.Ecology and Evolutionary BiologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/89661/1/mizzo_1.pd

Phase II Study of Arginine Deprivation Therapy With Pegargiminase in Patients With Relapsed Sensitive or Refractory Small-cell Lung Cancer.

BACKGROUND: Pre-clinical studies indicated that arginine-deprivation therapy using pegylated arginine deiminase (pegargiminase, ADI-PEG 20) may be effective in patients with argininosuccinate synthetase 1 (ASS1)-deficient small-cell lung cancer (SCLC). PATIENTS AND METHODS: Patients were enrolled into either a 'sensitive' disease cohort (≥ 90 days response to first-line chemotherapy) or a 'refractory' disease cohort (progression while on chemotherapy or < 90 days afterwards or ≥ third-line treatment). Patients received weekly intramuscular pegargiminase, 320 IU/m2 (36.8 mg/m2), until unacceptable toxicity or disease progression. The primary endpoint was tumor response assessed by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 with secondary endpoints including tolerability, pharmacodynamics, and immunogenicity. RESULTS: Between January 2011 and January 2014, 22 patients were enrolled: 9 in the sensitive disease cohort and 13 in the refractory disease cohort. At a pre-planned interim analysis, the best overall response observed was stable disease in 2 patients in each cohort (18.2%). Owing to the lack of response and slow accrual in the sensitive disease cohort, the study was terminated early. Pegargiminase treatment was well-tolerated with no unexpected adverse events or discontinuations. CONCLUSION: Although pegargiminase monotherapy in SCLC failed to meet its primary endpoint of RECIST-confirmed responses, more recent molecular stratification, including MYC status, may provide new opportunities moving forward

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost