Miracle-dz/UniFAR-FTUs huggingface dataset:
Stability of the Schwarzschild–de Sitter black hole in the dRGT massive gravity theory

The Schwarzschild-de Sitter solution in the Einstein theory with a positive cosmological constant $\Lambda=m^2/\alpha$ becomes an exact solution to the dRGT non-linear massive gravity theory with the mass parameter $m$ when the theory parameters $\alpha$ and $\beta$ satisfy the relation $\beta=\alpha^2$. We study the perturbative behaviour of this black hole solution in the non-linear dRGT theory with $\beta=\alpha^2$. We find that the linear perturbation equations become identical to those for the vacuum Einstein theory when they are expressed in terms of the gauge-invariant variables. This implies that this black hole is stable in the dRGT theory as far as the spacetime structure is concerned in contrast to the case of the bi-Schwarzschild solution in the bi-metric theory. However, we have also found a pathological feature that the general solution to the perturbation equations contain a single arbitrary function of spacetime coordinates. This implies a degeneracy of dynamics in the St\"uckelberg field sector at the linear perturbation level in this background. Physical significance of this degenercy depends on how the St\"uckelberg fields couple observable fields.
Rapid suppression of drive for a parasitic B chromosome

The persistence of parasitic B chromosomes in natural populations depends on both B ability to drive and host response to counteracting it. In the grasshopper Eyprepocnemis plorans, the B24 chromosome is the most widespread B chromosome variant in the Torrox area (Málaga, Spain). Its evolutionary success, replacing its ancestral neutralized B variant, B2, was based on meiotic drive in females, as we showed in a sample caught in 1992. In females collected six years later, mean B24 transmission ratio (kB) was 0.523, implying a very rapid decrease from the 0.696 observed in 1992. This shows that B24 neutralization is running very fast and suggests that it might most likely be based on a single gene of major effect.
Attributions and Attitudes of Mothers and Fathers in Colombia

SYNOPSIS Objective. The present study examined mean level similarities and differences as well as correlations between mothers' and fathers' attributions regarding successes and failures in caregiving situations and progressive versus authoritarian attitudes. Design. Interviews were conducted with mothers and fathers in 108 Colombian families. Results. Fathers reported higher uncontrollable success attributions and higher authoritarian attitudes than did mothers, whereas mothers reported higher modernity of attitudes than did fathers; only the gender differences related to parental attitudes remained significant after controlling for parents' age, education, and possible social desirability bias. The authors found medium effect sizes for concordance between parents in the same family for attributions regarding uncontrollable success and progressive attitudes after controlling for parents' age, education, and possible social desirability bias. Conclusions. This work elucidates ways that parent gender relates to attributions regarding parents' success and failure in caregiving and to progressive versus authoritarian parenting attitudes in Colombia.
Emotionally Troubled Teens’ Help-Seeking Behaviors

Many school-based suicide prevention programs do not show a positive impact on help-seeking behaviors among emotionally troubled teens despite their being at high risk for suicide. This study is a secondary analysis of the Surviving the Teens® program evaluation to determine its effect on help-seeking behaviors among troubled youth. Results showed significant increases in mean scores of the Behavioral Intent to Communicate with Important Others Regarding Emotional Health Issues subscale (p < .0005) from pretest to 3-month follow-up. There was a significant increase (p = .006) in mean scores of the Behavioral Intent Regarding Help-Seeking Behaviors when Suicidal subscale from pretest to posttest, but not at 3-month follow-up. Also, there was a significant increase (p = .016) in mean scores in the item “I would tell an adult if I was suicidal” from pretest to 3-month follow-up. These findings suggest that the Surviving the Teens program has a positive effect on help-seeking behaviors in troubled youth.
Radar–rain-gauge rainfall estimation for hydrological applications in small catchments

Abstract. The accurate evaluation of the precipitation's time–spatial structure is a critical step for rainfall–runoff modelling. Particularly for small catchments, the variability of rainfall can lead to mismatched results. Large errors in flow evaluation may occur during convective storms, responsible for most of the flash floods in small catchments in the Mediterranean area. During such events, we may expect large spatial and temporal variability. Therefore, using rain-gauge measurements only can be insufficient in order to adequately depict extreme rainfall events. In this work, a double-level information approach, based on rain gauges and weather radar measurements, is used to improve areal rainfall estimations for hydrological applications. In order to highlight the effect that precipitation fields with different level of spatial details have on hydrological modelling, two kinds of spatial rainfall fields were computed for precipitation data collected during 2015, considering both rain gauges only and their merging with radar information. The differences produced by these two precipitation fields in the computation of the areal mean rainfall accumulation were evaluated considering 999 basins of the region Calabria, southern Italy. Moreover, both of the two precipitation fields were used to carry out rainfall–runoff simulations at catchment scale for main precipitation events that occurred during 2015 and the differences between the scenarios obtained in the two cases were analysed. A representative case study is presented in detail.
Glycated haemoglobin, diabetes, and mortality in men

Editor—Khaw et al contribute to the substantial literature showing an association between measures of glycaemia and subsequent morbidity and mortality.1 They suggest that “preventive efforts need to consider not just those with established diabetes but whether it is possible to reduce the population distribution of HbA1c [glycated haemoglobin]. ” This implies that the determinant is the degree of hyperglycaemia. In the non-diabetic population, glycated haemoglobin principally reflects the fasting blood glucose concentration, which has been shown by several groups to predict morbidity and mortality. One of these groups, the DECODE (diabetes epidemiology: collaborative analysis of diagnostic criteria in Europe) Study Group, also measured the blood glucose concentration two hours after a load and found that fasting concentrations were not additionally predictive within two hour blood glucose categories.2 In a cross sectional study with carotid intima media thickness as a marker of atherosclerosis, blood glucose concentrations after a load (in particular the two hour value) and incremental values (that is, above fasting) were more strongly related to intima media thickness than were fasting glucose or glycated haemoglobin concentrations.3 Furthermore, in a population based study in Italy instability of fasting blood glucose concentrations over the years of observation was an independent predictor of cardiovascular mortality.4 Clearly there are several possible interpretations of these findings. One is that it is not glycaemia itself that is the risk factor but the disturbance(s) in the physiological mechanisms that regulate the blood glucose concentration. This explanation would agree with the disappointing results of hypoglycaemic treatment in type 2 diabetes, commented on by Barrett-Connor and Wingard.5
Identification of Bacteria Responsible for Ammonia Oxidation in Freshwater Aquaria

ABSTRACT Culture enrichments and culture-independent molecular methods were employed to identify and confirm the presence of novel ammonia-oxidizing bacteria (AOB) in nitrifying freshwater aquaria. Reactors were seeded with biomass from freshwater nitrifying systems and enriched for AOB under various conditions of ammonia concentration. Surveys of cloned rRNA genes from the enrichments revealed four major strains of AOB which were phylogenetically related to theNitrosomonas marina cluster, theNitrosospira cluster, or the Nitrosomonas europaea-Nitrosococcus mobilis cluster of the β subdivision of the class Proteobacteria. Ammonia concentration in the reactors determined which AOB strain dominated in an enrichment. Oligonucleotide probes and PCR primer sets specific for the four AOB strains were developed and used to confirm the presence of the AOB strains in the enrichments. Enrichments of the AOB strains were added to newly established aquaria to determine their ability to accelerate the establishment of ammonia oxidation. Enrichments containing the Nitrosomonas marina-like AOB strain were most efficient at accelerating ammonia oxidation in newly established aquaria. Furthermore, if the Nitrosomonas marina-like AOB strain was present in the original enrichment, even one with other AOB, only the Nitrosomonas marina-like AOB strain was present in aquaria after nitrification was established.Nitrosomonas marina-like AOB were 2% or less of the cells detected by fluorescence in situ hybridization analysis in aquaria in which nitrification was well established.
D german firms in service trade

We provide firm-level evidence concerning four key facts of services trade in Germany. First, not only firms classified as service firms, but also firms from all industries export and import services. Second, service trade patterns are fairly similar to those in goods trade. Most notably, service trade is dominated by a few large firms that serve many countries, sell several service products, and often export and import services. Differences in firms’ trade values are result from differences in all three margins of trade. Third, there is a strong concentration of firms on one core market and service. Fourth, the patterns are surprisingly similar for services exports and imports.
GENE TRANSFER BY F′ STRAINS OF ESCHERICHIA COLI K-12 I

Pittard, James (Yale University, New Haven, Conn.), John S. Loutit, and Edward A. Adelberg. Gene transfer by F′ strains of Escherichia coli K-12. I. Delay in initiation of chromosome transfer. J. Bacteriol. 85:1394–1401. 1963. —Two different F′ strains were found to transfer both F-merogenote and chromosomal markers to recipient strains. When zygotes having received different chromosomal markers from the male were selected, a high percentage of them were found to have also received F-merogenote markers under conditions in which the mating of more than one male cell with a single female cell was excluded. An analysis of the kinetics of zygote formation revealed that chromosomal markers began to be transferred from F′ strains 8 to 10 min later than from their analogous Hfr strains. The rate of chromosome transfer is the same from both F′ and Hfr strains, and the difference observed in kinetic experiments was shown not to be due to any difference between the sequence of chromosomal genes in the F′ and Hfr strains. F′ strains and Hfr strains showed no difference in ability to form specific pairs with female recipients shortly after mixing. The observed delay in the transfer of chromosomal markers from F′ cells thus means that, after specific pair formation, F′ cells take 8 to 10 min longer than Hfr cells to initiate chromosome transfer.
An Algebraic Approach to Automatic Construction of Structural Models

We present algebraic approach to the inductive learning of structural models and automatic construction of shape prototypes for character recognition on the basis of the algebraic description of curve structure proposed by Nishida and Mori (1991, 1992). A class in the structural models is a set of shapes that can be transformed continuously to each other. We consider an algebraic representation of continuous transformation of components of the shape, and give specific properties satisfied by each component in the class. The generalization rules in the inductive learning are specified from the viewpoints of continuous transformation of components and relational structure among the components. The learning procedure generalizes a pair of classes into one class incrementally and hierarchically in terms of the generalization rules. We show experimental results on handwritten numerals. >
Major bleeding complicating deep sternal infection after cardiac surgery.

OBJECTIVES This study was undertaken to determine the incidence and outcome of major bleeding complicating deep sternal infection after cardiac surgery, to identify predisposing factors and means of prevention, and to clarify management options. METHODS This was a retrospective study of 10,863 consecutive patients, of whom 213 (2.18%) acquired deep sternal infection. With 43 additional referrals, the total number of patients with deep sternal infection was 280. Deep sternal infection was managed by a two-stage scheme. Major bleeding was considered to be bleeding that occurred during or after operation for deep sternal infection from the heart, great vessels, or grafts, or bleeding requiring urgent exploration. RESULTS Fifteen patients (5.36%) had major bleeding. The incidences of deep sternal infection and bleeding were highest among patients undergoing coronary artery bypass grafting. Thirteen patients had underlying diseases (type 2 diabetes in 9 cases). Deep sternal infection was diagnosed a median of 15 days after reoperation. Bleeding originated from the right ventricle in 9 patients. In 4 patients bleeding was iatrogenic during surgery for wire removal (n = 2) or reconstruction (n = 2). In 11 it occurred 15 minutes to 15 days (median 2 days) after wire removal, as a result of shearing forces in 7 cases and of infection only in 4 cases. Three patients died immediately. The other 12 were operated on, 6 with complete cardiopulmonary bypass, 2 with femoral cannulation, and 4 without cardiopulmonary bypass. The immediate mortality was 26.7%; the overall mortality was 53.3%. The median length of hospitalization of surviving patients was 38 days. CONCLUSIONS The probability of development of major bleeding in patients with deep sternal infection was unrelated to the primary operation. The mortality associated with this complication was high. Meticulous technique during wire removal may decrease the risk of major bleeding. The impacts of cardiopulmonary bypass and of the technique and timing of sternal reconstruction remain undetermined.
T cell changes after combined nucleoside analogue therapy in HIV primary infection.

OBJECTIVE To characterize the immune changes after treatment of acute HIV-1 infection with triple nucleoside analogue therapy. DESIGN Immunological and virological parameters were monitored from day 0 to weeks 36-44 in eight patients [median CD4 cells = 451 cells/microl (range: 149-624), viral load = 4.8 log10 copies/ml (range: 6.5-3.3)] who started at time of primary HIV infection (PHI) a therapy including zidovudine (ZDV), didanosine (ddl), and lamivudine (3TC). METHODS Lymphoid subsets were evaluated on peripheral blood lymphocytes by four-colour flow cytometry using a panel of mAbs directed against differentiation and activation markers. RESULTS We observed a median -2.1 (range: -1; -3.3) log10 copies/ml viral load decrease and a median +158 cells/microl (range: +7 to +316) CD4 cell count increase at week 4 reaching normal CD4 cell count values of 761 CD4 cells/microl (range: 389-1153) at weeks 36-44. Virus undetectability was obtained at week 24 for all subjects. A rapid CD4 T cell amplification involved both memory and naive CD4 T cells. This was associated with a very rapid and significant decrease in activation markers [human leukocyte antigen-DR (HLA-DR), CD38] on both CD4 and CD8 T cell subsets together with a CD8+CD28+ cell increase as early as week 4. CONCLUSIONS These results show that early therapy with nucleoside analogues can correct the immunological abnormalities observed in CD4 and CD8 T cell subsets at the time of PHI. This early kinetics in T cell recovery appears to be faster than in established disease.
An Overview of Morphological Segmentation

Mathematical morphology offers a rich framework for segmenting images and video sequences. We propose a unified presentation of these tools, expressed as a small number of distance transforms on graphs. The classical approach based on watershed and markers is reinterpreted in a multiscale framework and new results are presented, considerably enlarging the palette of available tools.
Disinfecting capabilities of oxychlorine compounds

The bacterial virus f2 was inactivated by chlorine dioxide at acidic, neutral, and alkaline pH values. The rate of inactivation increased with increasing pH. Chlorine dioxide disproportionation products, chlorite and chlorate, were not active disinfectants. As chlorine dioxide solutions were degraded under alkaline conditions, they displayed reduced viricidal effectiveness, thereby confirming the chlorine dioxide free radical as the active disinfecting species.
Synonymous codon usage in chloroplast genome of Coffea arabica

Synonymous codon usage of 53 protein coding genes in chloroplast genome of Coffea arabica was analyzed for the first time to find out the possible factors contributing codon bias. All preferred synonymous codons were found to use A/T ending codons as chloroplast genomes are rich in AT. No difference in preference for preferred codons was observed in any of the two strands, viz., leading and lagging strands. Complex correlations between total base compositions (A, T, G, C, GC) and silent base contents (A3, T3, G3, C3, GC3) revealed that compositional constraints played crucial role in shaping the codon usage pattern of C. arabica chloroplast genome. ENC Vs GC3 plot grouped majority of the analyzed genes on or just below the left side of the expected GC3 curve indicating the influence of base compositional constraints in regulating codon usage. But some of the genes lie distantly below the continuous curve confirmed the influence of some other factors on the codon usage across those genes. Influence of compositional constraints was further confirmed by correspondence analysis as axis 1 and 3 had significant correlations with silent base contents. Correlation of ENC with axis 1, 4 and CAI with 1, 2 prognosticated the minor influence of selection in nature but exact separation of highly and lowly expressed genes could not be seen. From the present study, we concluded that mutational pressure combined with weak selection influenced the pattern of synonymous codon usage across the genes in the chloroplast genomes of C. arabica.
Elaphostrongylosis in Maritime Moose and Deer.

ON NOVEMBER 8, 1963, a three-and-a-half-year-old cow moose reported as having "moose sickness" was necropsied by one of the writers in the Chignecto Game Sanctuary, Nova Scotia. Examination of the brain and cranium revealed the presence of helminth parasites identified as Elaphostrongylus tentlis (19), but also known as Pneumostrongylus tenuis (2, 3, 4, 5) and Elaphostrongylus odocoilei (13) by other workers. E. tenuis is considered a deer parasite (2) and has been reported in deer from Ontario (4), Michigan (12, 13), Pennsylvania (1) and New York State (19). The incidence in deer herds is apparently high, as recent studies have shown that 41% of 172 adult deer in Ontario (4), 56.4% of 836 deer in Michigan (13), and 75% of 80 deer in Pennsylvania (1) were infected with E. tenuis. In deer, E. tenuis apparently are not associated with disease (4, 19), although Alibasoglu et al. (1) observed that under some circumstances these parasites are responsible for nervous disorders in deer. E. tenuis have also been found in moose (14, 19), in sheep (16, 17, 18, 19), and possibly in goats (19). In these supposedly abnormal hosts, E. tenuis sometimes cause extensive damage to the central nervous system (CNS) (90), resulting in abnormal behaviour, paralysis and other nervous symptoms ( 16, 17). In Nova Scotia, a disease of moose characterized by CNS derangement and known as "moose sickness" has been recognized for many years (7, 9, 10). A somewhat similar disease syndrome has also been recognized in moose in Minnesota (14, 15) and in Maine (9). Attempts to isolate the causative agent of this disease have not been successful. The absence of a pathogen led Benson (10) to suggest that the causative factor is nutritional, basically due to environmental changes resultant from recent climatic fluctuations in northeastern North America. Archibald (7) in 1960 reported the isolation of Listeria manocytogenes from the brain of a typically sick moose but since that time has repeatedly failed to isolate this organism from other similarly afflicted moose (8). While the etiology has remained obscure, the histopathological findings have suggested the possibility of a nematode encephalitis or encephalopathy (10). Recently Anderson (5, 6) reported on the experimental transmission of infective larvae of E. tentnis to two moose calves. Both animals developed signs of CNS involvement, such as lethargy, unwillingness to rise, weakness and inco-ordination of the hind legs, which became progressively more pronounced. Upon necropsy, lesions were confined to the CNS and E. tenntis were recovered from both calves.
HBS COVID-19 Global Policy Tracker

The HBS Covid-19 Global Policy Tracker is an initiative by the BGIE unit at Harvard Business School to collect and standardize economic policies implemented as a response to the coronavirus pandemic around the world. We focus on fiscal policy, monetary policy, and lockdowns and quantify government responses in common variables, units, and currencies to facilitate crosscountry comparisons. The database is updated in real-time with the efforts of several dozens of students at HBS and other Harvard schools. Acknowledgements: We are particularly grateful to all the students at HBS and other Harvard Schools who devoted their time and effort to collect and standardize the data. The team, at the time of writing, includes Alex DeVille, Angel Rodriguez, Anna Sakellariadis, Bhumika Agarwalla, Camille Gregory, Dvij Bajpai, Enrique Elias, Eufern Pan, Joaquin de la Maza, John Guo, Joyce Zhang, Lau Skovgaard, Marcia Ambrosi, Margherita Pignatelli, Ratnika Prasad, Rei Morimoto, Rohan Vora, Roni Luo, Ruth van Montfort, Ryan Yu, Soichiro Chiba, Sophia Lien, Ukasha Iqbal, Umang Sota. We are also grateful to Matt Weinzierl, Robin Greenwood, and other HBS faculty who helped at various points in this project, and to the many HBS alumni and other people who contributed policies through the website. Recommended Citation: Cavallo, Alberto, and Tannya Cai. "HBS Covid-19 Global Policy Tracker" Harvard Business School Working Paper, No. 20-110, April 2020. Available at www.globalpolicytracker. com