On the volumes and affine types of trades

A $[t]$-trade is a pair $T=(T_+, T_-)$ of disjoint collections of subsets (blocks) of a $v$-set $V$ such that for every $0\le i\le t$, any $i$-subset of $V$ is included in the same number of blocks of $T_+$ and of $T_-$. It follows that $|T_+| = |T_-|$ and this common value is called the volume of $T$. If we restrict all the blocks to have the same size, we obtain the classical $t$-trades as a special case of $[t]$-trades. It is known that the minimum volume of a nonempty $[t]$-trade is $2^t$. Simple $[t]$-trades (i.e., those with no repeated blocks) correspond to a Boolean function of degree at most $v-t-1$. From the characterization of Kasami--Tokura of such functions with small number of ones, it is known that any simple $[t]$-trade of volume at most $2\cdot2^t$ belongs to one of two affine types, called Type\,(A) and Type\,(B) where Type\,(A) $[t]$-trades are known to exist. By considering the affine rank, we prove that $[t]$-trades of Type\,(B) do not exist. Further, we derive the spectrum of volumes of simple trades up to $2.5\cdot 2^t$, extending the known result for volumes less than $2\cdot 2^t$. We also give a characterization of "small" $[t]$-trades for $t=1,2$. Finally, an algorithm to produce $[t]$-trades for specified $t$, $v$ is given. The result of the implementation of the algorithm for $t\le4$, $v\le7$ is reported.Comment: 30 pages, final version, to appear in Electron. J. Combi

Hidden Conformal Symmetry of Kerr-Bolt Spacetimes

We extend the recent proposal of hidden conformal symmetry to the four-dimensional spacetimes with rotational parameter and NUT twist. We consider the wave equation of a massless scalar field in background of Kerr-Bolt spacetimes and show in the "near region", the wave equation can be reproduced by the $SL(2,R)_L \times SL(2,R)_R$ Casimir quadratic operators. Moreover, we compute the microscopic entropy of the dual CFT by Cardy formula and find a perfect match to Bekenstein-Hawking entropy of Kerr-Bolt spacetimes. The absorption cross section of a near region scalar field also matches to microscopic absorption cross section of the dual CFT.Comment: 9 pages, re-organized and re-writtend, typos corrected, main results and conclusion unchange

Age determination of john's snapper (Lutjanus johni) using otolith sections

The age structure of John's Snapper (Luyanus johni) in Hormozgan waters, south Iran was studied. We conducted monthly sampling starting in May 1996 and ending in July 1997. Totally, 613 fish specimens were collected, of which 567 and 308 specimens were aged based on whole and sectioned otoliths respectively. The snappers were found to be aged from I to 17 years old. Results showed that each year only one pair of opaque and translucent zones was formed. Age determination based on the two methods was significantly different especially in the fish aged 1 to 6 years (P<0.05). Age-length relationship of the species based on sectioned otolith reading and total fish length using the least squares method was obtained as Lt = 89(1-e^ 165.476)). Also, the lengths weight relationship for the fish was determined as W=(4x10w5)xL2.8214

Age and growth of sind sardine (Sardinella sindensis) using otolith from Qeshm Island (Persian Gulf)

This is the first study of growth and age of Sardinella sindensis from coastal waters of Qeshm Island (Persian Gulf) based on the sectioned otolith reading method. In total, 128 fishes were collected randomly from purse seine commercial nets during March 2011 to February 2012. The annual formation of the growth rings were determined by counting the opaque and translucent zones occurrence at the outer margin of the otolith. The peak of opaque and translucent zones formation occurred in June and January, respectively. There was no significant differences between the sex ratio of males to females (p>0.05). The total length and body weight for both sexes ranged between (7.9-18.6 cm) and (3.98-55.69 g). In total, four age classes were determined, and the maximum age was recorded as 3.5 years. The most abundant individuals were counted in 1+ age class, while the least number of fishes belonged to the 3+ age class. The non-linear regression relationship between the length and age for combined sexes were fitted in Von Bertalanffy growth equation, and described as: TL= 20.8 (1-e^-0.54(t+ 0.54)). There was a strong relationship between the body weight and total length of the fishes (p>0.05), indicating that the growth type of S. sindensis is isometric. From the results of this study we concluded that S. sindensis is a fast-growing species with a short-life span. In order to obtain more reliable results about the age and growth of this species, we suggest that different methods of age determination should be used, combined with the evaluation of the factors affecting its growth for the management of optimum exploitation of the resources of this fish

Computationally efficient calibration of WATCLASS Hydrologic models using surrogate optimization

International audienceIn this approach, exploration of the cost function space was performed with an inexpensive surrogate function, not the expensive original function. The Design and Analysis of Computer Experiments(DACE) surrogate function, which is one type of approximate models, which takes correlation function for error was employed. The results for Monte Carlo Sampling, Latin Hypercube Sampling and Design and Analysis of Computer Experiments(DACE) approximate model have been compared. The results show that DACE model has a good potential for predicting the trend of simulation results. The case study of this document was WATCLASS hydrologic model calibration on Smokey-River watershed

An investigation on aquatics diversity and density in marine artificial reef, Moloo area of Bandar-e-Lengeh, Persian Gulf

Over-fishing of marine resources has endangered many commercial fish species in the world. Setting up artificial reefs is now considered an important way for marine stocks and fishing enhancement. The present study was designed to monitor fish abundance and species changes around a small and newly established artificial reef system in Moloo area at Bandar- e-Lengeh during two years after installation in September 2005. The anificial reef includes three types of concrete structures arranged in a seven by three grid. Each cross point was considered as a sampling station and two other stations were also selected from two sides of the system as control points. The CPUE and frequency of fishes in transect 7 with a mixed structure showed significant differences with Other 6 transects (P0.01). Although there were differences CPUE averages of different seasons, the ANOVA test of difference significance was negative. The t-test showed no significant differences between the abundance and of different species per trap per day and seasons. The dominant species were Epinephelus coioides, Plectorhinchus shoran Diagrama pictum, Siganus javus

The prevalence of cryptococcal antigenemia in serum of human immunodeficiency viruses-infected patients of iran

BACKGROUND: Cryptococcus species are the most prevalent opportunistic agents found in patients with HIV which may result in life-threatening cryptococcal meningitis (CM). A non-invasive way for diagnosis of CM is the detection of cryptococcal antigen (CrAg) in the blood to reduce either the mortality rate or the treatment complications associated with antiretroviral therapy. Not much information is available in CM among HIV patients in Iran. AIM: Thus, in the current study, we aimed to evaluate the prevalence of cryptococcal disease by antigen testing, possible associated factors, and outcomes in HIV-infected patients being managed in a referral HIV/TB hospital in Tehran-Iran. METHODS: In this cross-sectional study, blood samples were screened for CrAg using a rapid latex agglutination test between 2017 and 2018 at Masih Daneshvari Hospital (Tehran-Iran) as referral land center for HIV/TB patients. Based on CD4 counts, 106 HIV-positive infected patients including 101 (95.3) males and 5 (4.7) females with the mean ± standard deviation age of 42.40 ± 10.687 and 36.50 ± 6.403 years enrolled in the study. The patients were categorized into 4 groups, (a) &lt;50, (b) 50�100, (c) 101�200, and (d)&gt;200 CD4+ T cells/µL. Whole blood was obtained with EDTA (for flow cytometry of CD4 counts) or without for harvesting serum for determination of CrAg in serum. RESULTS: The results showed only one positive case for CrAg, indicating that CrAg is rare in Iranian HIV patients (overall estimation is lower than 0.01). CONCLUSIONS: With the paucity of information about the prevalence of cryptococcosis in Iran, there is a need for better screening tests and strategies for detection of CrAg in addition to the prevention and treatment approaches of CM. © 2020 Monireh Kamali, Payam Tabarsi, Khorshid Badihi, Esmaeil Mortaz

Comparison of quality of life between myopic patients with spectacles and contact lenses, and patients who have undergone refractive surgery

Purpose: The present study aims at investigating and comparing the vision-related quality of life of myopic persons who wear spectacles or contact lenses with those who have undergone refractive surgery. It also compares the vision-related quality of life of these two groups with that of emmetropes. Method: In this study, the questionnaire of evaluation instrument of refractive error in quality of life (NEI/RQL-42) was used to compare the quality of life between 154 myopic patients with spectacles and contact lenses, and 32 patients who have undergone refractive surgery. The two groups were also compared with 54 emmetropes. The questionnaire included 13 different subgroups (score 0-100) related to vision. Data was analyzed using SPSS software. Results: The overall score of quality of life in emmetropes (95.11 ± 4.23) was more than that in persons who had undergone refractive surgery (86.98 ± 4.73), and it was the least in the group wearing spectacles or contact lenses (78.30 ± 9.21), (P < 0/001). Furthermore, except for a glare variable, the studied groups indicated a statistically significant difference in all the thirteen subgroups of vision-related quality of life. Conclusion: Quality of life for people with myopia who had the refractive surgery was better than people with myopia who wore spectacles or contact lenses. Although quality of life in people with myopia who had the refractive surgery was less than emmetropia, it seems that refractive surgery improves quality of life of myopic patients. © 2015

Host genetics and viral load in primary HIV-1 infection: clear evidence for gene by sex interactions

© 2014, The Author(s).Research in the past two decades has generated unequivocal evidence that host genetic variations substantially account for the heterogeneous outcomes following human immunodeficiency virus type 1 (HIV-1) infection. In particular, genes encoding human leukocyte antigens (HLA) have various alleles, haplotypes, or specific motifs that can dictate the set-point (a relatively steady state) of plasma viral load (VL), although rapid viral evolution driven by innate and acquired immune responses can obscure the long-term relationships between HLA genotypes and HIV-1-related outcomes. In our analyses of VL data from 521 recent HIV-1 seroconverters enrolled from eastern and southern Africa, HLA-A*03:01 was strongly and persistently associated with low VL in women (frequency = 11.3 %, P  0.50). In a reduced multivariable model, age, sex, geography (clinical sites), previously identified HLA factors (HLA-B*18, B*45, B*53, and B*57), and the interaction term for female sex and HLA-A*03:01 collectively explained 17.0 % of the overall variance in geometric mean VL over a 3-year follow-up period (P < 0.0001). Multiple sensitivity analyses of longitudinal and cross-sectional VL data yielded consistent results. These findings can serve as a proof of principle that the gap of “missing heritability” in quantitative genetics can be partially bridged by a systematic evaluation of sex-specific associations

The Medical Research Council (UK)/Uganda Virus Research Institute Uganda Research Unit on AIDS--'25 years of research through partnerships'.

For the past 25 years, the Medical Research Council/Uganda Virus Research Institute Uganda Research Unit on AIDS has conducted research on HIV-1, coinfections and, more recently, on non-communicable diseases. Working with various partners, the research findings of the Unit have contributed to the understanding and control of the HIV epidemic both in Uganda and globally, and informed the future development of biomedical HIV interventions, health policy and practice. In this report, as we celebrate our silver jubilee, we describe some of these achievements and the Unit's multidisciplinary approach to research. We also discuss the future direction of the Unit; an exemplar of a partnership that has been largely funded from the north but led in the south