Modularity and community detection in bipartite networks

The modularity of a network quantifies the extent, relative to a null model network, to which vertices cluster into community groups. We define a null model appropriate for bipartite networks, and use it to define a bipartite modularity. The bipartite modularity is presented in terms of a modularity matrix B; some key properties of the eigenspectrum of B are identified and used to describe an algorithm for identifying modules in bipartite networks. The algorithm is based on the idea that the modules in the two parts of the network are dependent, with each part mutually being used to induce the vertices for the other part into the modules. We apply the algorithm to real-world network data, showing that the algorithm successfully identifies the modular structure of bipartite networks.Comment: RevTex 4, 11 pages, 3 figures, 1 table; modest extensions to conten

Individual Differences in Cerebral Blood Flow in Area 17 Predict the Time to Evaluate Visualized Letters

Sixteen subjects closed their eyes and visualized uppercase letters of the alphabet at two sizes, as small as possible or as large as possible while remaining “visible.” Subjects evaluated a shape characteristic of each letter (e.g., whether it has any curved lines), and responded as quickly as possible. Cerebral blood flow was normalized to the same value for each subject, and relative blood flow was computed for a set of regions of interest. The mean response time for each subject in the task was regressed onto the blood flow values. Blood flow in area 17 was negatively correlated with response time (r = -0.65), as was blood flow in area 19 (r = -0.66), whereas blood flow in the inferior parietal lobe was positively correlated with response time (r = 0.54). The first two effects persisted even when variance due to the other correlations was removed. These findings suggest that individual differences in the activation of specific brain loci are directly related to performance of tasks that rely on processing in those loci.Psycholog

Motional diminishing of optical activity: a novel method for studying molecular dynamics in liquids and plastic crystals

Molecular dynamics calculations and optical spectroscopy measurements of weakly active infrared modes are reported. The results are qualitatively understood in terms of the "motional diminishing" of IR lines, a process analogous to the motional narrowing of a nuclear magnetic resonance (NMR) signal. In molecular solids or liquids where the appropriate intramolecular resonances are observable, motional diminishing can be used to study the fluctuations of the intermolecular interactions having time scales of 1psec to 100psec.Comment: RevTeX in LaTeX file, 12 preprint pages, 4 ps figures included. Also available from http://insti.physics.sunysb.edu/~mmartin/pubs.html Accepted for publication in Chem. Phys. Let

Alcohol Use Disorders And Antiretroviral Therapy Among Prisoners With Hiv/aids In Argentina

While Argentina has significantly improved access to HIV care and antiretroviral therapy (ART) for both the general population and prisoners, the prevalence of alcohol use disorders (AUDs) among HIV-infected prisoners and their relationship to accessing ART in Argentina is currently unknown. This study aims to characterize the substance abuse patterns of HIV-infected prisoners in Argentina and to assess the independent correlates of receipt of pre-incarceration ART. An anonymous, cross-sectional survey of 100 HIV-infected federal prisoners was conducted in the Buenos Aires municipality from July-December 2010. AUDs were assessed using the AUDIT scale. A majority (63 per cent) of participants met criteria for AUDs, 45 per cent of subjects were diagnosed with HIV in prison and one-quarter had initiated ART during the current incarceration. In addition, over one-third (35 per cent) of participants did not receive ART during the pre-incarceration period despite receiving it upon incarceration. This correlated significantly with the presence of having an AUD (AOR 0.20, 95 per cent CI 0.06-0.74, p = 0.016). AUDs are prevalent among HIV-infected prisoners in Argentina and are significantly related to not receiving ART in the community among those who meet treatment criteria and receive ART in prison. While Argentina has provided an exemplary model of HIV-related health care reform within its prisons, future efforts to provide screening and treatment for AUDs are needed to improve the health of the nation\u27s incarcerated population

Visual Mental Imagery Activates Topographically Organized Visual Cortex: PET Investigations

Cerebral blood flow was measured using positron emission tomography (PET) in three experiments while subjects performed mental imagery or analogous perceptual tasks. In Experiment 1, the subjects either visualized letters in grids and decided whether an X mark would have fallen on each letter if it were actually in the grid, or they saw letters in grids and decided whether an X mark fell on each letter. A region identified as part of area 17 by the Talairach and Tournoux (1988) atlas, in addition to other areas involved in vision, was activated more in the mental imagery task than in the perception task. In Experiment 2, the identical stimuli were presented in imagery and baseline conditions, but subjects were asked to form images only in the imagery condition; the portion of area 17 that was more active in the imagery condition of Experiment 1 was also more activated in imagery than in the baseline condition, as was part of area 18. Subjects also were tested with degraded perceptual stimuli, which caused visual cortex to be activated to the same degree in imagery and perception. In both Experiments 1 and 2, however, imagery selectively activated the extreme anterior part of what was identified as area 17, which is inconsistent with the relatively small size of the imaged stimuli. These results, then, suggest that imagery may have activated another region just anterior to area 17. In Experiment 3, subjects were instructed to close their eyes and evaluate visual mental images of upper case letters that were formed at a small size or large size. The small mental images engendered more activation in the posterior portion of visual cortex, and the large mental images engendered more activation in anterior portions of visual cortex. This finding is strong evidence that imagery activates topographically mapped cortex. The activated regions were also consistent with their being localized in area 17. Finally, additional results were consistent with the existence of two types of imagery, one that rests on allocating attention to form a pattern and one that rests on activating stored visual memories.Psycholog

Being Black in Maine\u27 webinar offered by Greater Bangor Area Branch NAACP, UMaine Alumni Association for Martin Luther King Day

In recognition of Martin Luther King Day, a free online public webinar, “Being Black in Maine: Lived Experience and the Prospect for Change,” will be livestreamed on YouTube on Jan. 18 from 5 to 6:15 p.m. The webinar, co-sponsored by the Greater Bangor Area Branch NAACP and the University of Maine Alumni Association, will include a sustained panel discussion, relevant short presentations and a special announcement of a new civil rights speaker series

Genome Resources for Climate‐Resilient Cowpea, an Essential Crop for Food Security

Cowpea (Vigna unguiculata L. Walp.) is a legume crop that is resilient to hot and drought‐prone climates, and a primary source of protein in sub‐Saharan Africa and other parts of the developing world. However, genome resources for cowpea have lagged behind most other major crops. Here we describe foundational genome resources and their application to the analysis of germplasm currently in use in West African breeding programs. Resources developed from the African cultivar IT97K‐499‐35 include a whole‐genome shotgun (WGS) assembly, a bacterial artificial chromosome (BAC) physical map, and assembled sequences from 4355 BACs. These resources and WGS sequences of an additional 36 diverse cowpea accessions supported the development of a genotyping assay for 51 128 SNPs, which was then applied to five bi‐parental RIL populations to produce a consensus genetic map containing 37 372 SNPs. This genetic map enabled the anchoring of 100 Mb of WGS and 420 Mb of BAC sequences, an exploration of genetic diversity along each linkage group, and clarification of macrosynteny between cowpea and common bean. The SNP assay enabled a diversity analysis of materials from West African breeding programs. Two major subpopulations exist within those materials, one of which has significant parentage from South and East Africa and more diversity. There are genomic regions of high differentiation between subpopulations, one of which coincides with a cluster of nodulin genes. The new resources and knowledge help to define goals and accelerate the breeding of improved varieties to address food security issues related to limited‐input small‐holder farming and climate stress

Ageing: A Dialogue

In April 2021, longing to learn first-hand about ageing philosophically, Valery Vino reached out to the legendary Arnold Berleant (who was 89 at the time of writing), to see whether he might be interested in recording a dialogue to this theme, with a companion of his choice. Berleant selected his ideal collaborator Michael Alpert, book designer and collector, poet, senior, and treasured friend. Over the following six months, a rich tapestry of leisurely reading, contemplation and discussion unfolded, culminating in an unrehearsed, free-flowing conversation about ageing, which has been recorded, lightly edited and offered here for readers to share

ADCC Develops Over Time during Persistent Infection with Live-Attenuated SIV and Is Associated with Complete Protection against SIVmac251SIV_{mac}251 Challenge

Live-attenuated strains of simian immunodeficiency virus (SIV) routinely confer apparent sterilizing immunity against pathogenic SIV challenge in rhesus macaques. Understanding the mechanisms of protection by live-attenuated SIV may provide important insights into the immune responses needed for protection against HIV-1. Here we investigated the development of antibodies that are functional against neutralization-resistant SIV challenge strains, and tested the hypothesis that these antibodies are associated with protection. In the absence of detectable neutralizing antibodies, Env-specific antibody-dependent cell-mediated cytotoxicity (ADCC) emerged by three weeks after inoculation with SIVΔnef, increased progressively over time, and was proportional to SIVΔnef replication. Persistent infection with SIVΔnef elicited significantly higher ADCC titers than immunization with a non-persistent SIV strain that is limited to a single cycle of infection. ADCC titers were higher against viruses matched to the vaccine strain in Env, but were measurable against viruses expressing heterologous Env proteins. In two separate experiments, which took advantage of either the strain-specificity or the time-dependent maturation of immunity to overcome complete protection against $SIV_{mac}251$ challenge, measures of ADCC activity were higher among the SIVΔnef-inoculated macaques that remained uninfected than among those that became infected. These observations show that features of the antibody response elicited by SIVΔnef are consistent with hallmarks of protection by live-attenuated SIV, and reveal an association between Env-specific antibodies that direct ADCC and apparent sterilizing protection by SIVΔnef

Operaciones secretas inglesas en España durante la Segunda Guerra Mundial

Aigunos miembros de los servicios ingleses de Información involucrados en la Guerra Civil, sobre todo Kim Philby y el capitán de Navio Hillgarth, siguieron ocupando cargos de importancia en los servicios secretos durante la Segunda Guerra Mundial. Las principales actividades de los servicios secretos ingleses en España incluían preservar la seguridad de Gibraltar, contrarrestar el trabajo de los agentes alemanes en el Estrecho, y desenmascarar a los espías españoles dirigidos por el Abwehr. Este artículo se ocupa especialmente de las dificultades de organizar el trabajo del llamado Special Operations Executive, en relación con la planificación de actividades guerrilleras y de sabotajes en caso de una ocupación de España por fuerzas militares alemanas.British specialists such as Kim Philby and Captain Alan Hillgarth, who had been involved in Intelligence services during the Spanish Civil War, contributed to the activities of the British Secret Services in Spain during the Second World War. Their main activities included the security of Gibraltar, counteracting German Intelligence in the Straits, and unmasking Spanish agents controlled by the Abwehr. This article concentrates on the particular difficulties of organising the work of the Special Operations Executive and its plans for guerrilla-type activity in the case of a German military occupation of Spain, whose neutrality, in the view of Great Britain, had to be carefully preserved