The trade-off between egg size and fecundity in the bruchid beetle Callosobruchus maculatus : a quantitative genetic approach.

Female Callosobruchus maculatus have fixed reproductive resources to allocate to offspring. It is predicted that the option of investing in a few large eggs or many small eggs will result in a trade-off between egg size and fecundity in this species. The aim of this study was to examine this proposed trade-off and obtain empirical evidence for its significance in the life history of C. maculatus. Breeding and selection experiments were used to measure the genetic correlation between egg size and fecundity as evidence for the existence of the trade-off. Selection experiments also allowed egg size to be manipulated to investigate its intrinsic effects on offspring fitness. Chapter 1 introduces life history theory and trade-off from the distinct but complementary perspectives of optimality theory and evolutionary genetics. Empirical methods that can be used to measure trade-offs are evaluated with respect to the egg size versus fecundity trade-off and the biology of C. maculatus. In Chapter 2 the general experimental methods are described. Phenotypic correlations involving egg size, fecundity and other life history traits are measured in Chapter 3. Egg size is not phenotypically correlated with fecundity but varies with maternal emergence weight and age. Correlative effects of egg size on offspring fitness appear to be due to effects on offspring body weight and development rate. The presence of genetic variation in egg size and fecundity are demonstrated in Chapter 4. In Chapter 5 the genetic correlation between egg size and fecundity is measured by means of a half sib breeding experiment. A negative genetic correlation of low precision was obtained. Chapter 6 provides a second estimate of the genetic correlation from an experiment in which egg size was increased and decreased by artificial selection. The correlated response in fecundity was downwards in both directions of selection which was not consistent with the proposed trade-off. The genetic correlation estimated was positive. Reasons for the unexpected response are discussed. The effects of selection for egg size on other life history traits is examined in Chapter 7. Only development rate, fecundity and emergence weight in females had changed after selection. Chapter 8 discusses what the quantitative experiments have revealed about the trade-off between egg size and fecundity and assesses the merits of the methodologies

Symmetric arrangement of mitochondria:plasma membrane contacts between adjacent photoreceptor cells regulated by Opa1

Mitochondria are known to play an essential role in photoreceptor function and survival that enables normal vision. Within photoreceptors, mitochondria are elongated and extend most of the inner-segment length, where they supply energy for protein synthesis and the phototransduction machinery in the outer segment, as well as acting as a calcium store. Here, we examined the arrangement of the mitochondria within the inner segment in detail using three-dimensional (3D) electron microscopy techniques and show they are tethered to the plasma membrane in a highly specialized arrangement. Remarkably, mitochondria and their cristae openings align with those of neighboring inner segments. The pathway by which photoreceptors meet their high energy demands is not fully understood. We propose this to be a mechanism to share metabolites and assist in maintaining homeostasis across the photoreceptor cell layer. In the extracellular space between photoreceptors, Müller glial processes were identified. Due to the often close proximity to the inner-segment mitochondria, they may, too, play a role in the inner-segment mitochondrial arrangement as well as metabolite shuttling. OPA1 is an important factor in mitochondrial homeostasis, including cristae remodeling; therefore, we examined the photoreceptors of a heterozygous Opa1 knockout mouse model. The cristae structure in the Opa1+/− photoreceptors was not greatly affected, but the mitochondria were enlarged and had reduced alignment to neighboring inner-segment mitochondria. This indicates the importance of key regulators in maintaining this specialized photoreceptor mitochondrial arrangement

Parametric instabilities in magnetized multicomponent plasmas

This paper investigates the excitation of various natural modes in a magnetized bi-ion or dusty plasma. The excitation is provided by parametrically pumping the magnetic field. Here two ion-like species are allowed to be fully mobile. This generalizes our previous work where the second heavy species was taken to be stationary. Their collection of charge from the background neutral plasma modifies the dispersion properties of the pump and excited waves. The introduction of an extra mobile species adds extra modes to both these types of waves. We firstly investigate the pump wave in detail, in the case where the background magnetic field is perpendicular to the direction of propagation of the pump wave. Then we derive the dispersion equation relating the pump to the excited wave for modes propagating parallel to the background magnetic field. It is found that there are a total of twelve resonant interactions allowed, whose various growth rates are calculated and discussed.Comment: Published in May 2004; this is a late submission to the archive. 14 pages, 8 figure

A SURVEY OF THE HAEMATOLOGICAL, NUTRITIONAL AND BIOCHEMICAL STATE OF THE RURAL ELDERLY WITH PARTICULAR REFERENCE TO VITAMIN C

A survey of the rural elderly has been carried out to determine basic haematological and biochemical data, and to establish a pattern of living for this 'well' population. The blood parameters related to diet, such as haemoglobin, folate, cholesterol, vitamin C etc., show considerable changes with increasing age in the male but little significant change in the female. The vitamin C status for , both sexes compares favourably with that reported by other workers studying the urban elderly. The biochemical and haematological data derived provide a normal range with which the 'sick' elderly can be compared. The subjects were generally active and independent in spite of (or because of) a somewhat Spartan existence

A case of non-Hodgkin's lymphoma associated with hypercalcemia.

A patient with a diffuse, small cleaved cell, non-Hodgkin's lymphoma associated with marked hypecalcemia was described. Antibody to the adult T-cell leukemia-lymphoma virus was absent. Although bone marrow was infiltrated by lymphoma cells, destructive or lytic bone lesions could not be detected. The serum level of immunoreactive parathyroid hormone C-terminal (PTH-C) was normal. The serum level of 1, 25-dihydroxyvitamin D was lower than normal. This case suggests that other humoral substances produced by lymphoma cells may be responsible for hypercalcemia.&#60;/P&#62;</p

King Pin? A Case Study of a Middle Market Drug Broker

The article is concerned with 'middle market' drug distribution, based on research that involved prison interviews with middle and upper level drug dealers and interviews with a range of enforcement personnel. It offers a preliminary discussion of different definitions of the 'middle market', where various forms of drug brokerage connect up different levels of drug markets. It goes on to provide a detailed case study of a single middle market drug distribution network, illustrating the complexity of such operations, the way in which drug brokers work as free trading entrepreneurs, and the often misunderstood role of violence in serious crime networks such as these

Photometric Observation And Period Study of GO Cygni

Photometric observations of GO Cyg were performed during the July-October 2002, in B and V bands of Johnson system. Based on Wilson's model, the light curve analysis were carried out to find the photometric elements of the system. The O-C diagram which is based on new observed times of minima suggests a negative rate of period variation (dP/dt<0) for the system.Comment: 12 pages, 6 figures, 4 tables, submitted to Ap&S

The police and the far right in Greece::a case study of police voting behaviour in Athens

The electoral advance of the far right party of Golden Dawn has left a clear mark on the Greek parliamentary elections of 2012. A less debated aspect of these results involves the extent of the electoral influence of Golden Dawn among police personnel. Using electoral data from two districts in Greece’s capital city, this paper explores the extent of that influence among major front line police units based in those localities. Our analysis obtains clear indications that Golden Dawn’s presence has been much more emphatic among police personnel than among the general public. These results warrant further exploration of this development, particularly in light of the possibility that far-right ideology may influence the character of everyday policing in Greece and the use of police discretion at the detriment of vulnerable or politically undesirable groups

Genetic variability of the grey wolf Canis lupus in the Caucasus in comparison with Europe and the Middle East: distinct or intermediary population?

Despite continuous historical distribution of the grey wolf (Canis lupus) throughout Eurasia, the species displays considerable morphological differentiation that resulted in delimitation of a number of subspecies. However, these morphological discontinuities are not always consistent with patterns of genetic differentiation. Here we assess genetic distinctiveness of grey wolves from the Caucasus (a region at the border between Europe and West Asia) that have been classified as a distinct subspecies C. l. cubanensis. We analysed their genetic variability based on mtDNA control region, microsatellite loci and genome-wide SNP genotypes (obtained for a subset of the samples), and found similar or higher levels of genetic diversity at all these types of loci as compared with other Eurasian populations. Although we found no evidence for a recent genetic bottleneck, genome-wide linkage disequilibrium patterns suggest a long-term demographic decline in the Caucasian population – a trend consistent with other Eurasian populations. Caucasian wolves share mtDNA haplotypes with both Eastern European and West Asian wolves, suggesting past or ongoing gene flow. Microsatellite data also suggest gene flow between the Caucasus and Eastern Europe. We found evidence for moderate admixture between the Caucasian wolves and domestic dogs, at a level comparable with other Eurasian populations. Taken together, our results show that Caucasian wolves are not genetically isolated from other Eurasian populations, share with them the same demographic trends, and are affected by similar conservation problems