Gravitational Waves with Orbital Angular Momentum

Compact orbiting binaries like the black hole binary system observed in GW150914 carry large amount of orbital angular momentum. The post-ringdown compact object formed after merger of such a binary configuration has only spin angular momentum, and this results in a large orbital angular momentum excess. One significant possibility is that the gravitational waves generated by the system carry away this excess orbital angular momentum. An estimate of this excess is made. Arguing that plane gravitational waves cannot possibly carry any orbital angular momentum, a case is made in this paper for gravitational wave beams carrying orbital angular momentum, akin to optical beams. Restricting to certain specific beam-configurations, we predict that such beams may produce a new type of strain, in addition to the longitudinal strains measured at aLIGO for GW150914 and GW170817. Current constraints on post-ringdown spins, derived within the planewave approximation of gravitational waves, therefore stand to improve. The minimal modification that might be needed on a laser-interferometer detector (like aLIGO or VIRGO) to detect such additional strains is also briefly discussed.Comment: 8 pages, 4 figures Version to appear in EPJ

Characterization of Clinical Isolates of Enterococci with Special Reference to Glycopeptide Susceptibility at a Tertiary Care Center of Eastern Nepal

Background. Enterococci, once considered as a harmless commensal of intestine, have now emerged as medically important pathogens and are associated with both community-acquired and nosocomial infections. They bear the potential to exhibit resistance against all commonly used antibiotics either by inherent or acquired mechanism, posing a therapeutic challenge. Objectives. This study aimed to characterize enterococci up to the species level and study their antibiogram with special regard to vancomycin. Methods. A descriptive cross-sectional study was conducted in the Department of Microbiology, B.P. Koirala Institute of Health Sciences, Dharan, Nepal, from February to May 2017. A total of 91 enterococcal isolates recovered from clinical specimens were investigated in this study. Their identification and speciation were done according to standard microbiological guidelines. Kirby–Bauer disc diffusion technique was used to study antimicrobial susceptibility pattern, whereas minimum inhibitory concentration of vancomycin was determined by the agar dilution method, with reference to Clinical and Laboratory Standards Institute guidelines. Results. Seven different species of enterococci were isolated, E. faecalis and E. faecium accounting about 45% each. The other species encountered were E. avium, E. cecorum, E. dispar, E. durans, and E. raffinosus. Highest proportion of antimicrobial susceptibility was recorded for linezolid (97.8%), followed by teicoplanin (95.6%) and high-level gentamicin (81.3%). Sensitivity to vancomycin was seen in 79.1% isolates. Likewise, 82.1% of urinary strains were susceptible to nitrofurantoin. A total of 4 disparities were observed between the disc diffusion technique and agar dilution method in determining vancomycin resistance. Multidrug resistance was observed in 31.9% isolates. The overall prevalence of vancomycin-resistant enterococci based on the standard minimum inhibitory concentration method was 25.3%. Conclusions. Enterococcus faecalis and E. faecium were the predominant species in causing enterococcal infections. The alarming rise in prevalence of vancomycin and multidrug resistance strains warrants immediate, adequate, and efficient surveillance program to prevent and control its spread

Study of biofilm formation and antibiotic resistance pattern of gram-negative Bacilli among the clinical isolates at BPKIHS, Dharan

Abstract Objectives Gram-negative bacilli are the common causative agents for community-acquired, nosocomial and opportunistic infections. The recent upsurge of biofilm, as well as beta-lactamases producing strains, have synergistically led to the extensive dissemination of multi-drug resistant gram-negative bacilli. This study was carried out with an intention to detect the biofilm formation by gram-negative bacilli and determine their antibiogram along with the detection of extended-spectrum beta-lactamases (ESBLs) and metallo-beta-lactamases (MBLs) production. Results Among 314 isolates, Escherichia coli (38%) were the predominant isolates followed by Acinetobacter spp. (20%), Klebsiella spp. (16%), and Pseudomonas spp. (12%). Overall, 197 (62.73%) of isolates were biofilm positive. 84 (26.75%) and 51 (16.24%) were confirmed as ESBL and MBL producers respectively. The association between MBL production and biofilm formation was statistically significant (χ2 = 10.20, P value= 0.002) whereas it was insignificant between ESBL and biofilm production (χ2 = 0.006, P-value= 0.937). Most of the biofilm and MBL producing strains were multi-drug resistant

Urinary Calculi: A Microbiological and Biochemical Analysis at a Tertiary Care Hospital in Eastern Nepal

Background. The occurrence of urinary tract infection in presence of urolithiasis is frequently noted; however, microbial agents of urolithiasis and their antimicrobial susceptibility patterns remain underinvestigated. This study aimed to identify the microorganisms isolated from urine and stone matrices to determine their antimicrobial susceptibility, to find the association between the pathogens of urine and stone matrices, and to perform the biochemical analysis of stones. Methods. A total of 88 cases of urolithiasis admitted for elective stone removal at Department of surgery, B.P. Koirala Institute of Health Sciences (BPKIHS), were enrolled. Preoperative urine culture and postoperative stone culture were performed. Isolation, identification, and AST were done by the standard microbiological technique. Further qualitative biochemical analysis of stones was also attempted. Result. Among 88 stone formers recruited, culture of urine, whole stone, and nidus yielded the growth of bacteria 44, 32, and 30, respectively. Bacteria isolated from urine culture correlated with those from stone matrices with a sensitivity of 90%, specificity of 79.69%, PPV of 63.64%, and NPV of 95.45%. Escherichia coli (46.7%) was the most common bacteria followed by Klebsiella pneumoniae (16.7%) and Proteus mirabilis (13.3%) from urine and stone cultures. Almost all the uropathogens isolated were susceptible to commonly used antibiotics. Calcium oxalate (84.1%) was common biochemical constituent found in stone formers followed by calcium oxalate + phosphate (8%). Conclusions. The association of microorganism isolated from urine and nidus culture was significant that can predict the source of infective stone; however, in some cases, microorganisms and the antimicrobial susceptibility pattern from urine and nidus were different. This study emphasizes the use of appropriate antimicrobial agents to prevent the regrowth of residual stones and minimize the risk of infectious complications after surgical removal of stones

Clinical, etiological and antimicrobial susceptibility profile of pediatric urinary tract infections in a tertiary care hospital of Nepal

Abstract Background Urinary tract infection (UTI) is one of most common pediatric infections. The study was designed to assess the clinical profile, common bacterial microorganisms causing UTI and their antimicrobial susceptibility patterns at B. P. Koirala Institute of Health Sciences (BPKIHS) hospital. Methods This is a prospective cross-sectional study conducted at Department of Microbiology and Infectious Diseases for 6 months (January to June 2018). A total of 1962 non-repetitive urine specimens (midstream, nappy pad, catheter aspirated) of pediatric patients (0–14 years age) suspected of UTI were obtained in the Microbiology laboratory. Clinical data was obtained from requisition form and hospital software. Culture and bacterial identification was done by using standard microbiological guidelines. Antimicrobial susceptibility testing was done by Kirby-Bauer disc diffusion method following clinical and laboratory standards institute (CLSI) guidelines. Resistance to methicillin and vancomycin were confirmed by calculating minimum inhibitory concentration using broth dilution method. Results Among 1962 samples, 314 (16%) were positive for bacterial infection. Fever, irritability and poor feeding was the most common symptoms in neonates while older children presented with fever and urinary symptoms. E. coli was reported the most common etiological agent (53%), followed by Enterococcus faecalis (22%), Klebsiella pneumoniae (7%) and Staphylococcus aureus (7%). Multidrug resistant (MDR) isolates accounted for 32% of isolates, while 5% were extensively drug resistant (XDR). Fourty percentage of gram-negative bacilli were ESBL producer, 38% of S. aureus were methicillin resistant Staphylococcus aureus (MRSA) and 5% E. faecalis were vacomycin resistant enterococci (VRE). E coli was highly resistant to Ampicillin (87%), Ceftriaxone (62%) and Ofloxacin (62%). Amikacin (11% resistance) and Nitrofurantoin (5% resistance) are the most effective drugs for gram-negative bacilli (GNB) while vancomycin and linezolid are functional against gram-positive cocci. Conclusions High-level antimicrobial resistance was observed in pediatric UTI with alarming incidence superbugs like MDR, XDR, ESBL and MRSA. Regular surveillance should be carried out to determine the local prevalence of organisms and antimicrobial susceptibilities in order to guide the proper management of children

A review on developing high-performance ZE41 magnesium alloy by using bulk deformation and surface modification methods

Magnesium (Mg) alloys are generally used in light-weight structural applications due to their higher specific strength. However, the usage of these Mg alloys is limited due to their poor formability at room temperature, which is attributed to lower count of slip systems associated with the hcp crystal structure. To address these limitations, several new magnesium alloys and also many processing strategies have been developed and reported in the literature. ZE41 Mg is an alloy with significant quantities of zinc (Zn) and rare earth (RE) elements and has emerged as a promising material for aerospace, automotive, electronics, biomedical and many other industries. To make this alloy more competitive and viable, it should possess better mechanical and corrosion properties. Hence, the current paper reviews the effect of bulk mechanical processing on grain refinement, microstructural modification, and corresponding changes in the mechanical behaviour of ZE41 Mg alloy. Further, the effect of various surface modification techniques on altering the surface microstructure and surface properties such as wear and corrosion are also briefly summarized and presented. This review also discusses the challenges and the future perspectives in developing high-performing ZE41 Mg alloys

Application of satellite derived sea-surface temperature for estimation of fish catch : A pilot study

152-154Sea surface temperatures have been obtained from NOAA-MCSST charts of 1986 and 1987 using interpolation method for Orissa coast, to evaluate their association with marine fish catch, as obtained from the landing stations in the form of monthly means. The fish catch increases with the decrease of temperatures. On an average 50% of variations in the fish catch can be explained with the help of variations in temperatures in this region

Asymptomatic Bacteriuria in Pregnant Women

Introduction: Asymptomatic bacteriuria is the significant presence of bacteria in urine of an individual without symptoms. The aim of the study is to determine the prevalence of asymptomatic bacteriuria in pregnant women. Methods: This study was a prospective study conducted in the department of Obstetrics and Gynaecology at B. P. Koirala Institute of Health Sciences. The duration of the study was six months from January to June 2012. A total of 600 pregnant women were enrolled. All women were clinically identified to have no signs and symptoms of UTI. Clean catch midstream urine sample was collected from each patient into a sterile vial. The urine samples were examined for microscopic and culture sensitivity test. Results: Out of 600 pregnant women, 52 were positive for significant bacteriuria with a prevalence rate of 8.7%. There was a significant difference in prevalence of asymptomatic bacteriuria with respect to trimester (p=0.005). Age did not show any significant difference in the prevalence of asymptomatic bacteriuria (p=0.807). There was not any significant difference in the prevalence of asymptomatic bacteriuria with respect to parity (p=0.864) and booking status (p=0.397). Escherichia coli (35%), Acinetobacter species (15%), Enterococcus species (12%) and Klebsiella pneumoniae (10%) were the common isolates. Most of the isolates were sensitive either to Nitrofurantoin, Norfloxacin or Amikacin. Conclusions: Asymptomatic bacteriuria is common in pregnancy. Urine culture sensitivity should be carried out routinely on all pregnant patients in order to prevent the dangerous complications associated with it. Keywords: asymptomatic bacteriuria in pregnancy; urine culture and sensitivity

Asymptomatic Bacteriuria in Pregnant Women

Introduction: Asymptomatic bacteriuria is the significant presence of bacteria in urine of an individual without symptoms. The aim of the study is to determine the prevalence of asymptomatic bacteriuria in pregnant women. 
 Methods: This study was a prospective study conducted in the department of Obstetrics and Gynaecology at B. P. Koirala Institute of Health Sciences. The duration of the study was six months from January to June 2012. A total of 600 pregnant women were enrolled. All women were clinically identified to have no signs and symptoms of UTI. Clean catch midstream urine sample was collected from each patient into a sterile vial. The urine samples were examined for microscopic and culture sensitivity test. 
 Results: Out of 600 pregnant women, 52 were positive for significant bacteriuria with a prevalence rate of 8.7%. There was a significant difference in prevalence of asymptomatic bacteriuria with respect to trimester (p=0.005). Age did not show any significant difference in the prevalence of asymptomatic bacteriuria (p=0.807). There was not any significant difference in the prevalence of asymptomatic bacteriuria with respect to parity (p=0.864) and booking status (p=0.397). Escherichia coli (35%), Acinetobacter species (15%), Enterococcus species (12%) and Klebsiella pneumoniae (10%) were the common isolates. Most of the isolates were sensitive either to Nitrofurantoin, Norfloxacin or Amikacin. 
 Conclusions: Asymptomatic bacteriuria is common in pregnancy. Urine culture sensitivity should be carried out routinely on all pregnant patients in order to prevent the dangerous complications associated with it. 
 Keywords: asymptomatic bacteriuria in pregnancy; urine culture and sensitivity