516 research outputs found
Dynamics of auto- and heterotrophic picoplankton and associated viruses in Lake Geneva
Microbial dynamics have rarely been investigated in Lake Geneva, known as
the largest lake in western Europe. From a 5-month survey, we report dynamic
patterns of free-living virus, bacteria and small phytoplankton abundances
in response to a variety of environmental parameters. For the first time, we
fractionated the primary production to separate the contribution of
different size-related biological compartments and measured both bacterial
and viral production in addition to experiments conducted to quantify the
virus-induced bacterial mortality. We observed marked seasonal and vertical
variations in picocyanobacteria, bacteria and virus abundances and
production. The contribution of picoplankton and nanoplankton production to
the total primary production was high (reaching up to 76% of total
primary production) in November and the spring–summer transition period,
respectively. The impact of viral lysis on both bacteria and
picocyanobacteria was significantly higher than grazing activities.
Virus-induced picocyanobacterial mortality reached up to 66% of cell
removal compared to virus induced (heterotrophic) bacterial mortality, which
reached a maximum of 34% in July. Statistical analyzes revealed that
temperature and top-down control by viruses are among important factors
regulating the picocyanobacterial dynamics in this lake. More generally
speaking, our results add to the growing evidence and accepted view nowadays
that viruses are an important actor of freshwater microbial dynamics and
more globally of the functioning of the microbial food webs
Falling for fake news: investigating the consumption of news via social media
In the so called ‘post-truth’ era, characterized by a loss of public trust in various institutions, and the rise of ‘fake news’ disseminated via the internet and social media, individuals may face uncertainty about the veracity of information available, whether it be satire or malicious hoax. We investigate attitudes to news delivered by social media, and subsequent verification strategies applied, or not applied, by individuals. A survey reveals that two thirds of respondents regularly consumed news via Facebook, and that one third had at some point come across fake news that they initially believed to be true. An analysis task involving news presented via Facebook reveals a diverse range of judgement forming strategies, with participants relying on personal judgements as to plausibility and scepticism around sources and journalistic style. This reflects a shift away from traditional methods of accessing the news, and highlights the difficulties in combating the spread of fake news
Human Resource Practices in IT industry: An empirical research of Bengaluru city
This research article aims to “To measure the impact of human resource practices determinants on employee performance in IT industry”. The paper applies data reduction using Exploratory Factor Analysis (EFA) on a sample of 312 respondents drawn from 6 IT companies in the Bangalore city and condenses a set of 22 statements converted into a five human resource practices determinants. The present study proposes a model of the impact of human resource practices determinants on employee performance. The study found that compensation, recruitment and selection, training & development, performance appraisal and promotion are impacting significantly the employee performance. Therefore, IT companies should focus on the above factors to enrich human resource practices determinants. The study investigated the impact of determinants of HR practices on employee performance in IT industry concluded that compensation had the highest impact on the employee performance followed by recruitment and selection, training & development, performance appraisal and promotion
Low Complexity Multiplier-less Modified FRM Filter Bank using MPGBP Algorithm
The design of a low complexity multiplier-less narrow transition band filter bank for the channelizer of multi-standard software-defined radio (SDR) is investigated in this paper. To accomplish this, the modal filter and complementary filter in the upper and lower branches of the conventional Frequency Response Masking (FRM) architecture are replaced with two power-complementary and linear phase filter banks. Secondly, a new masking strategy is proposed to fully exploit the potential of the numerous spectra replicas produced by the interpolation of the modal filter, which was previously ignored in the existing FRM design. In this scheme, the two masking filters are appropriately modulated and alternately masked over the spectra replicas from 0 to 2, to generate even and odd channels. This Alternate Masking Scheme (AMS) increases the potency of the Modified FRM (ModFRM) architecture for the design of a computationally efficient narrow transition band uniform filter bank (termed as ModFRM-FB). Finally, by combining the adjoining ModFRM-FB channels, Non-Uniform ModFRM-FB (NUModFRM-FB) for extracting different communication standards in the SDR channelizer is created. To reduce the total power consumption of the architecture, the coefficients of the proposed system are made multiplier-less using the Matching Pursuits Generalized Bit-Planes (MPGBP) algorithm. In this method, filter coefficients are successively approximated using a dictionary of vectors to give a sum-of-power-of-two (SOPOT) representation. In comparison to all other general optimization techniques, such as genetic algorithms, the suggested design method stands out for its ease of implementation, requiring no sophisticated optimization or exhaustive search schemes. Another notable feature of the suggested approach is that, in comparison to existing methods, the design time for approximation has been greatly reduced. To further bring down the complexity, adders are reused in recurrent SOPOT terms using the Common Sub-expression Elimination (CSE) technique without compromising the filter performance
Low Complexity Multiplier-less Modified FRM Filter Bank using MPGBP Algorithm
The design of a low complexity multiplier-less narrow transition band filter bank for the channelizer of multi-standard software-defined radio (SDR) is investigated in this paper. To accomplish this, the modal filter and complementary filter in the upper and lower branches of the conventional Frequency Response Masking (FRM) architecture are replaced with two power-complementary and linear phase filter banks. Secondly, a new masking strategy is proposed to fully exploit the potential of the numerous spectra replicas produced by the interpolation of the modal filter, which was previously ignored in the existing FRM design. In this scheme, the two masking filters are appropriately modulated and alternately masked over the spectra replicas from 0 to 2, to generate even and odd channels. This Alternate Masking Scheme (AMS) increases the potency of the Modified FRM (ModFRM) architecture for the design of a computationally efficient narrow transition band uniform filter bank (termed as ModFRM-FB). Finally, by combining the adjoining ModFRM-FB channels, Non-Uniform ModFRM-FB (NUModFRM-FB) for extracting different communication standards in the SDR channelizer is created. To reduce the total power consumption of the architecture, the coefficients of the proposed system are made multiplier-less using the Matching Pursuits Generalized Bit-Planes (MPGBP) algorithm. In this method, filter coefficients are successively approximated using a dictionary of vectors to give a sum-of-power-of-two (SOPOT) representation. In comparison to all other general optimization techniques, such as genetic algorithms, the suggested design method stands out for its ease of implementation, requiring no sophisticated optimization or exhaustive search schemes. Another notable feature of the suggested approach is that, in comparison to existing methods, the design time for approximation has been greatly reduced. To further bring down the complexity, adders are reused in recurrent SOPOT terms using the Common Sub-expression Elimination (CSE) technique without compromising the filter performance
Our experience with gastrointestinal stromal tumors over a period of three years from a tertiary care centre
Background: Gastrointestinal stromal tumors (GIST) are the most common mesenchymal neoplasms of the gastrointestinal tract (GIT). Stomach being the commonest site in the GIT, it can occur in the extra-intestinal areas like mesentery, retroperitoneum, omentum and prostate. Exceptionally rare in urinary bladder. Commonly present as solid tumors but cystic degeneration can occur in large tumors especially in extra intestinal regions and may be mistaken for ovarian tumors. We have studied GISTs for a period of 3 years and presenting certain rare entities we encountered. Aim of the study was to study the age and sex prevalence and relative distribution of GISTs in gastrointestinal and extra gastrointestinal (EGIST) areas in various sites, and morphological features in relation to certain rare variants.Methods: 18 surgical resected specimens of gastrointestinal and extra gastrointestinal masses received at the department of pathology, Andhra Medical College, Visakhapatnam, were studied for a period of 3 years from July 2013 to June 2016.Results: GISTs were found to be common in male patients with male to female ratio of 2:1. GISTs of Small bowel showed female predilection. 40% of EGISTs were of larger size and malignant.Conclusions: Age, sex and morphological features were consistent with literature. Small intestine showed slightly increased prevalence when compared to stomach and large intestine. Tumor size and mitotic count were predictors of outcome. EGISTs showed higher incidence in women and pelvic GISTs have to be carefully evaluated to differentiate them from ovarian tumors
Internal herniation of bowel through the mesodiverticular band in adults - rare presentation - managed by laparoscopy: report of a case
Meckel’s diverticulam is the most common congenital anomaly of gastrointestinal tract. Reporting a case of small bowel obstruction due to internal herniation though the mesodiverticular band, which is a very rare presentation in adults- managed by laparoscopic division of mesodiverticular band. A 35 year old patient, presented to the emergency department with intestinal obstruction. Investigations are suggestive of small bowel obstruction. Diagnostic laparoscopy was done. A meckel’s diverticulum with herniation of small bowel through the mesodiverticular band is found. The mesodiverticular band is divided. As the meckel’s diverticulam was wide mouthed directiculectomy was not done. It can be managed safely by laparoscopy and with less incidence of complications. Morbidity is minimal and rapid return of intestinal function can be achieved
PREPARATION AND EVALUATION OF QUETIAPINE FUMARATE MICROEMULSIONS: A NOVEL DELIVERY SYSTEM
Objective: In the present study, the main objective is to improve solubility and bioavailability of Quetiapine fumarate by formulation into micro emulsion.
Method: The Quetiapine fumarate micro emulsion was formulated by using mixture of Isopropyl myristate and oleic acid as oil phase, Tween-80 as surfactant, Isopropyl alcohol and Ethanol mixture as co-surfactant by phase titration method. The prepared formulations were evaluated for Limpidity (% transmittance), droplet size, Zeta potential, Electrical conductivity, Rheology, pH, percentage of drug (assay), emulsifying time, in vitro drug diffusion studies and ex vivo permeation studies.
Results and conclusion: The Optimized micro emulsion (Micro emulsion 11) formulation containing Quetiapine fumarate (25mg), Surfactant mixture (50%w/w), Oil (12%w/w) and distilled water (38%w/w) has a droplet size of 26.70 nm with a zeta potential of -5.62 millivolts. The micro emulsion was characterized and compared with the pure drug suspension. Microemulsion showed 31.25 fold increased solubility than that of pure drug suspension. In vitro drug release and ex vivo permeation study results were comparable and correlative. The Microemulsion 11 formulation showed 1.4763 times more drug release than that of pure drug suspension. The formulation was found to be stable for three months.
Keywords: Microemulsion, Phase titration method, Quetiapine Fumarate, Emulsifying time
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