Mechanization of dairy farming in Bangladesh

The mechanization status of dairy farming in Bangladesh is not mentionable. In every steps of the farming operation, indigenous systems have been practiced in most of the farms. This study has been conducted to assess mechanization status in dairy farming. The selected areas of this study were Bangladesh Agricultural University (BAU) dairy farm, Mymensingh, Rural Development Academy (RDA) dairy farm, Bogra and four small, four medium and two large farms in Sirajganj district. Most mechanized RDA dairy farm and rest of the non-mechanized farms were selected for this study. The field survey was conducted by interviewing identified sample respondents with pre-determined interview schedules to cover all selected locations. Most of the farms have no specific designed farm building with specific space per animal, feeding alley, manger, gutter and drainage system, ventilation system. Even the manure management system in study area was very poor. A biogas plant can utilize manure properly. Milking machine and chopper machine were only found in BAU and RDA dairy farms. Spacing per animal for dairy cow was 3.65 m2, for pregnant cow was 9.30 m2, for dry cow or heifer was 1.37 m2, and for calf was 1.31 m2 respectively. Mangers in a pen barn were about 0.5-1.25 m wide and 0.5-1 m depth which varies for dairy cow, heifer, calf, and bull individually. All farms in study areas found natural ventilation system. Concentrates require per day for dairy cow, dry cow, heifer, bull calf, cow calf and mature bull were 3.4, 2.2, 1.2, 0.5, 1.01 and 5.2 kg respectively. The amount of maize for bull is 2.4 kg, for dairy cow is 1.4 kg and lowest amount for bull calf is 140 g per head. Due to lack of knowledge and unfamiliarity farmers do not accept machinery like milking machine, chopper machine etc. Installation of partial mechanization can contribute to convert indigenous into modernization with gross productivity of dairy farming systems in Bangladesh

A hyperpromiscuous antitoxin protein domain for the neutralization of diverse toxin domains

Toxin–antitoxin (TA) gene pairs are ubiquitous in microbial chromosomal genomes and plasmids as well as temperate bacteriophages. They act as regulatory switches, with the toxin limiting the growth of bacteria and archaea by compromising diverse essential cellular targets and the antitoxin counteracting the toxic effect. To uncover previously uncharted TA diversity across microbes and bacteriophages, we analyzed the conservation of genomic neighborhoods using our computational tool FlaGs (for flanking genes), which allows high-throughput detection of TA-like operons. Focusing on the widespread but poorly experimentally characterized antitoxin domain DUF4065, our in silico analyses indicated that DUF4065-containing proteins serve as broadly distributed antitoxin components in putative TA-like operons with dozens of different toxic domains with multiple different folds. Given the versatility of DUF4065, we have named the domain Panacea (and proteins containing the domain, PanA) after the Greek goddess of universal remedy. We have experimentally validated nine PanA-neutralized TA pairs. While the majority of validated PanA-neutralized toxins act as translation inhibitors or membrane disruptors, a putative nucleotide cyclase toxin from a Burkholderia prophage compromises transcription and translation as well as inducing RelA-dependent accumulation of the nucleotide alarmone (p)ppGpp. We find that Panacea-containing antitoxins form a complex with their diverse cognate toxins, characteristic of the direct neutralization mechanisms employed by Type II TA systems. Finally, through directed evolution, we have selected PanA variants that can neutralize noncognate TA toxins, thus experimentally demonstrating the evolutionary plasticity of this hyperpromiscuous antitoxin domain

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

Bioinformatik, evolution och revolution för vår förståelse av toxin-antitoxinsystem

Bacteria experience a wide range of natural challenges during their life cycles, to which they must respond and adapt to live. Under stressed conditions such as amino acid starvation, bacteria slow down their growth mechanism by producing small alarmone nucleotides guanosine pentaphosphate (pppGpp) and tetraphosphate (ppGpp), collectively referred to as (p)ppGpp. Accumulation of (p)ppGpp results in a comprehensive alteration in cellular metabolism. The alarmone (p)ppGpp is produced and degraded by enzymes belonging to the RelA/SpoT Homologue (RSH) protein family, named for their sequence similarity to the RelA and SpoT enzymes of Escherichia coli. The members of the RSH protein family can be classified into long multi-domain RSHs and short single-domain RSHs. Long RSH enzymes such as RelA and SpoT, carry both the (p)ppGpp hydrolysis (HD) domain and (p)ppGpp synthesis (SYNTH) domain in the N-terminal domain enzymatic region (NTD), in combination with additional domains in the C-terminal domain regulatory region (CTD). Short single-domain RSHs can be divided into small alarmone hydrolases (SAHs) carrying the HD domain, and small alarmone synthetases (SASs) that only have the SYNTH domain. At the beginning of my PhD, I studied the diversity of RSH proteins across the tree of life. I identified 35,615 RSH proteins from analyses of 24,072 genomes. I used large-scale phylogenetic analyses to classify the RSH proteins into 13 long RSHs, 11 SAHs and 30 SASs subfamilies. To address why bacteria often carry multiple SASs in the same genome and predict new functions, I developed a computational tool called FlaGs – standing for Flanking Genes – to analyse the conservation of genomic neighbourhoods in large datasets. I also developed a web-based version of FlaGs, called webFlaGs, that is publicly accessible and is used by biologists all over the world.  The application of FlaGs to SAS RSHs led to the discovery that multiple SAS subfamilies are encoded in conserved and frequently overlapping two or three-gene architecture, reminiscent of toxin−antitoxin (TA) systems. Five SAS representatives from the FaRel, FaRel2, PhRel, PhRel2 and CapRel subfamilies were experimentally validated as toxins (toxSASs) that are neutralised by the products of six neighbouring antitoxin genes. The toxSAS enzyme FaRel from Cellulomonas marina is encoded as the central gene of a conserved three-gene architecture and acts through the production of nucleotide alarmone ppGpp and its unusual toxic analogue ppApp, causing a significant depletion of ATP and GTP. FaRel toxicity can be countered by both downstream and upstream cognate antitoxins. The latter contains a SAH domain that neutralises toxicity through degradation of ppGpp as well as ppApp.  Combining phylogenetic and FlaGs analyses we have discovered that the DUF4065 domain of unknown function is a widely distributed antitoxin domain in putative TA-like operons with dozens of distinct toxic domains. Nine DUF4065-containing antitoxins and their cognate toxins were experimentally validated as TA pairs using toxicity neutralisation assays. These antitoxins form complexes with their diverse cognate toxins. Given the versatility of DUF4065, we have renamed this domain Panacea. We hypothesise that there are multiple hyperpromiscuous antitoxins like Panacea that can be associated with many non-homologous toxin domains, which may also be hyperpromiscuous. Thus, TA systems across all bacteria can be represented as a network of toxin and antitoxin domain combinations, with hyperpromiscuous domains being hubs in the network. To test this and compute a network, I developed a new, iterative version of FlaGs, called NetFlax (standing for Network-FlaGs for toxins and antitoxins), that can identify TA-like gene architectures in an unsupervised manner and generate a toxin-antitoxin domain interaction network. The results from NetFlax verify our strategy since we have rediscovered multiple previously characterised TAs as well as brand new ones. We find that Panacea is unusual but not unique in its hyperpromiscuity and our network indicates the presence of novel hyperpromiscuous domains still to be explored. Our findings also demonstrate how a core network of TAs is evolutionarily linked to various accessory genome systems, including conjugative transfer and phage defence mechanisms. The existing network can potentially be a framework on which future discoveries of the biological role of TAs can be mapped. Number in series missing in publication. </p

Bioinformatik, evolution och revolution för vår förståelse av toxin-antitoxinsystem

Bacteria experience a wide range of natural challenges during their life cycles, to which they must respond and adapt to live. Under stressed conditions such as amino acid starvation, bacteria slow down their growth mechanism by producing small alarmone nucleotides guanosine pentaphosphate (pppGpp) and tetraphosphate (ppGpp), collectively referred to as (p)ppGpp. Accumulation of (p)ppGpp results in a comprehensive alteration in cellular metabolism. The alarmone (p)ppGpp is produced and degraded by enzymes belonging to the RelA/SpoT Homologue (RSH) protein family, named for their sequence similarity to the RelA and SpoT enzymes of Escherichia coli. The members of the RSH protein family can be classified into long multi-domain RSHs and short single-domain RSHs. Long RSH enzymes such as RelA and SpoT, carry both the (p)ppGpp hydrolysis (HD) domain and (p)ppGpp synthesis (SYNTH) domain in the N-terminal domain enzymatic region (NTD), in combination with additional domains in the C-terminal domain regulatory region (CTD). Short single-domain RSHs can be divided into small alarmone hydrolases (SAHs) carrying the HD domain, and small alarmone synthetases (SASs) that only have the SYNTH domain. At the beginning of my PhD, I studied the diversity of RSH proteins across the tree of life. I identified 35,615 RSH proteins from analyses of 24,072 genomes. I used large-scale phylogenetic analyses to classify the RSH proteins into 13 long RSHs, 11 SAHs and 30 SASs subfamilies. To address why bacteria often carry multiple SASs in the same genome and predict new functions, I developed a computational tool called FlaGs – standing for Flanking Genes – to analyse the conservation of genomic neighbourhoods in large datasets. I also developed a web-based version of FlaGs, called webFlaGs, that is publicly accessible and is used by biologists all over the world.  The application of FlaGs to SAS RSHs led to the discovery that multiple SAS subfamilies are encoded in conserved and frequently overlapping two or three-gene architecture, reminiscent of toxin−antitoxin (TA) systems. Five SAS representatives from the FaRel, FaRel2, PhRel, PhRel2 and CapRel subfamilies were experimentally validated as toxins (toxSASs) that are neutralised by the products of six neighbouring antitoxin genes. The toxSAS enzyme FaRel from Cellulomonas marina is encoded as the central gene of a conserved three-gene architecture and acts through the production of nucleotide alarmone ppGpp and its unusual toxic analogue ppApp, causing a significant depletion of ATP and GTP. FaRel toxicity can be countered by both downstream and upstream cognate antitoxins. The latter contains a SAH domain that neutralises toxicity through degradation of ppGpp as well as ppApp.  Combining phylogenetic and FlaGs analyses we have discovered that the DUF4065 domain of unknown function is a widely distributed antitoxin domain in putative TA-like operons with dozens of distinct toxic domains. Nine DUF4065-containing antitoxins and their cognate toxins were experimentally validated as TA pairs using toxicity neutralisation assays. These antitoxins form complexes with their diverse cognate toxins. Given the versatility of DUF4065, we have renamed this domain Panacea. We hypothesise that there are multiple hyperpromiscuous antitoxins like Panacea that can be associated with many non-homologous toxin domains, which may also be hyperpromiscuous. Thus, TA systems across all bacteria can be represented as a network of toxin and antitoxin domain combinations, with hyperpromiscuous domains being hubs in the network. To test this and compute a network, I developed a new, iterative version of FlaGs, called NetFlax (standing for Network-FlaGs for toxins and antitoxins), that can identify TA-like gene architectures in an unsupervised manner and generate a toxin-antitoxin domain interaction network. The results from NetFlax verify our strategy since we have rediscovered multiple previously characterised TAs as well as brand new ones. We find that Panacea is unusual but not unique in its hyperpromiscuity and our network indicates the presence of novel hyperpromiscuous domains still to be explored. Our findings also demonstrate how a core network of TAs is evolutionarily linked to various accessory genome systems, including conjugative transfer and phage defence mechanisms. The existing network can potentially be a framework on which future discoveries of the biological role of TAs can be mapped. Number in series missing in publication. </p

A holin/peptidoglycan hydrolase-dependent protein secretion system

Gram-negative bacteria have evolved numerous pathways to secrete proteins across their complex cell envelopes. Here, we describe a protein secretion system which uses a holin membrane protein in tandem with a cell wall editing enzyme to mediate the secretion of substrate proteins from the periplasm to the cell exterior. The identity of the cell wall editing enzymes employed was found to vary across biological systems. For instance, the chitinase secretion pathway of Serratia marcescens uses an endopeptidase to facilitate secretion, whereas the secretion of Typhoid toxin in Salmonella enterica serovar Typhi relies on a muramidase. Various families of holins are also predicted to be involved. Genomic analysis indicates that this pathway is conserved and implicated in the secretion of hydrolytic enzymes and toxins for a range of bacteria. The pairing of holins from different families with various types of peptidoglycan hydrolases suggests that this secretion pathway evolved multiple times. We suggest that the complementary bodies of evidence presented is sufficient to propose that the pathway be named the Type 10 Secretion System (TXSS). Potential mechanisms for secretion across the outer membrane are discussed.Special Issue: Protein Secretion and Transport</p

Context-based sensing of orthosomycin antibiotics by the translating ribosome

Orthosomycin antibiotics inhibit protein synthesis by binding to the large ribosomal subunit in the tRNA accommodation corridor, which is traversed by incoming aminoacyl-tRNAs. Structural and biochemical studies suggested that orthosomycins block accommodation of any aminoacyl-tRNAs in the ribosomal A-site. However, the mode of action of orthosomycins in vivo remained unknown. Here, by carrying out genome-wide analysis of antibiotic action in bacterial cells, we discovered that orthosomycins primarily inhibit the ribosomes engaged in translation of specific amino acid sequences. Our results reveal that the predominant sites of orthosomycin-induced translation arrest are defined by the nature of the incoming aminoacyl-tRNA and likely by the identity of the two C-terminal amino acid residues of the nascent protein. We show that nature exploits this antibiotic-sensing mechanism for directing programmed ribosome stalling within the regulatory open reading frame, which may control expression of an orthosomycin-resistance gene in a variety of bacterial species