Gig Workers: Walking a Tightrope Without a Safety Net

Annually every spring—until the COVID-19 pandemic which began in March 2020, professional sports teams turn to their own budding prospects. Rookie drafts garner media attention and propel the possibility of staggering salaries into the headlines. Undrafted free agents, for their part, begin searching for jobs. With a lesser celebrity profile, many American workers have themselves become free agents in an economy transformed by technology The static newspaper classified ads of the past have been joined by vast online platforms, such as TaskRabbit and Freelancer.com, that allow jobseekers to connect with individuals seeking a diverse range of services—from graphic design and data entry to home furniture assembly. Yet, this flexibility comes with a flipside, potentially placing workers on a path to economic insecurity and at the crossroads of a complicated legal debate about what rights and benefits they are due

Tight Bounds for MIS in Multichannel Radio Networks

Daum et al. [PODC'13] presented an algorithm that computes a maximal independent set (MIS) within $O(\log^2 n/F+\log n \mathrm{polyloglog} n)$ rounds in an $n$-node multichannel radio network with $F$ communication channels. The paper uses a multichannel variant of the standard graph-based radio network model without collision detection and it assumes that the network graph is a polynomially bounded independence graph (BIG), a natural combinatorial generalization of well-known geographic families. The upper bound of that paper is known to be optimal up to a polyloglog factor. In this paper, we adapt algorithm and analysis to improve the result in two ways. Mainly, we get rid of the polyloglog factor in the runtime and we thus obtain an asymptotically optimal multichannel radio network MIS algorithm. In addition, our new analysis allows to generalize the class of graphs from those with polynomially bounded local independence to graphs where the local independence is bounded by an arbitrary function of the neighborhood radius.Comment: 37 pages, to be published in DISC 201

The Potential of Restarts for ProbSAT

This work analyses the potential of restarts for probSAT, a quite successful algorithm for k-SAT, by estimating its runtime distributions on random 3-SAT instances that are close to the phase transition. We estimate an optimal restart time from empirical data, reaching a potential speedup factor of 1.39. Calculating restart times from fitted probability distributions reduces this factor to a maximum of 1.30. A spin-off result is that the Weibull distribution approximates the runtime distribution for over 93% of the used instances well. A machine learning pipeline is presented to compute a restart time for a fixed-cutoff strategy to exploit this potential. The main components of the pipeline are a random forest for determining the distribution type and a neural network for the distribution's parameters. ProbSAT performs statistically significantly better than Luby's restart strategy and the policy without restarts when using the presented approach. The structure is particularly advantageous on hard problems.Comment: Eurocast 201

Association of timing of adverse childhood experiences and caregiver support with regionally specific brain development in adolescents

Importance: Few data are available to inform the associations and timing of the associations between adversity, caregiver support, and brain outcomes. Consideration of timing has important public health implications to inform more precise prevention strategies. Objective: To evaluate the timing and regional specificity of the association between adverse childhood experiences (ACEs) and caregiver support to structural development of limbic and striatal brain regions in middle childhood and adolescence. Design, Setting, and Participants: This 15-year developmental, neuroimaging cohort study included 211 children and their caregivers screened from day care centers and preschools in the St Louis, Missouri, metropolitan area during the preschool period, with an additional 4 waves of neuroimaging at school age through adolescence from November 14, 2007, to August 29, 2017. The cohort was oversampled for preschoolers with elevated symptoms of depression using a brief screener. Data analysis was performed from March 19, 2019, to July 26, 2019. Main Outcomes and Measures: Volumes in adolescence and developmental trajectories of volumes of the amygdala, hippocampus, caudate, subgenual cingulate, and insula during 4 waves of scanning; ACEs and observed caregiver support at preschool and school age; and volumes of amygdala, hippocampus, insula, and subgenual cingulate during 4 waves of scanning. Results: A total of 211 children (107 [50.7%] male) completed at least 1 scan. At preschool (mean [SD] age, 5.5 [0.8] years), ACE data were available for 164 children (84 [51.2%] male) and maternal support data for 155 children; at school age (mean [SD], 8.3 [1.2] years), ACE data were available for 172 children and maternal support data for 146 children. Unique patterns of the association between ACEs and support were found, with an association between the interaction of preschool ACEs and school-age support and the development of the hippocampus (t = -2.27; P = .02) and amygdala (t = -2.12; P = .04). A buffering hypothesis was not confirmed because high caregiver support was more strongly associated with the development of these regions only in the context of low ACEs. In contrast, preschool ACEs (t = -2.30; P = .02) and support (t = 2.59; P = .01) had independent associations with the development of the caudate. Conclusions and Relevance: The findings suggest that there are unique regional associations of support and adversity with key brain structures important for emotional regulation. Results may inform the timing and potential targets of preventive action for the range of poor developmental outcomes

Multivariate analysis of risk factors associated with genital ulcer disease among incarcerated males in Sindh

Objective: To evaluate the potential risk behaviors associated with the lifetime risk of self reported genital ulcer disease (GUD) among prison inmates.SETTING: Prison inmates from 14 prisons of Sindh Province.Methods: A cross-sectional study was conducted on 3395 prison inmates during July to December, 1994. A questionnaire was used to assess the lifetime risk of self-reported GUD (whether or not the subject was ever affected with GUD up to present age) and to investigate demographic markers and risk behaviors for their possible association with lifetime risk of GUD using logistic regression analysis.Results: The reported lifetime risk of GUD in the study sample was 11.4% (386/3395). In final multivariate logistic regression model the sexual behaviors which were independently associated with GUD were having sexual intercourse with female (adjusted OR = 1.7; 95% CI: 1.3-2.3, P = 0.0002), sexual intercourse with a prostitute (adjusted OR = 1.5; 95% CI: 1.2-2.0, P = 0.0008), sexual intercourse with man (adjusted OR = 2.2; 95% CI: 1.7-2.7, P = \u3c 0.001) and sexual intercourse with man during current incarceration (adjusted OR = 1.9; 95% CI: 1.2-2.9, P = 0.0071).CONCLUSION: Health education needs to re-enforce monogamous relationship for high risk groups such as in our study. Although infrequent condom use was not a risk factor for GUD in this study, yet based on the results of previous studies, promotion of condom use should be the component of health education program

Beeping a Maximal Independent Set

We consider the problem of computing a maximal independent set (MIS) in an extremely harsh broadcast model that relies only on carrier sensing. The model consists of an anonymous broadcast network in which nodes have no knowledge about the topology of the network or even an upper bound on its size. Furthermore, it is assumed that an adversary chooses at which time slot each node wakes up. At each time slot a node can either beep, that is, emit a signal, or be silent. At a particular time slot, beeping nodes receive no feedback, while silent nodes can only differentiate between none of its neighbors beeping, or at least one of its neighbors beeping. We start by proving a lower bound that shows that in this model, it is not possible to locally converge to an MIS in sub-polynomial time. We then study four different relaxations of the model which allow us to circumvent the lower bound and find an MIS in polylogarithmic time. First, we show that if a polynomial upper bound on the network size is known, it is possible to find an MIS in O(log^3 n) time. Second, if we assume sleeping nodes are awoken by neighboring beeps, then we can also find an MIS in O(log^3 n) time. Third, if in addition to this wakeup assumption we allow sender-side collision detection, that is, beeping nodes can distinguish whether at least one neighboring node is beeping concurrently or not, we can find an MIS in O(log^2 n) time. Finally, if instead we endow nodes with synchronous clocks, it is also possible to find an MIS in O(log^2 n) time.Comment: arXiv admin note: substantial text overlap with arXiv:1108.192

Inequalities in Care-seeking for Febrile Illness of Under-five Children in Urban Dhaka, Bangladesh

Fever is an easily-recognizable primary sign for many serious childhood infections. In Bangladesh, 31% of children aged less than five years (under-five children) die from serious infections, excluding confirmed acute respiratory infections or diarrhoea. Understanding healthcare-seeking behaviour for children with fever could provide insights on how to reduce this high rate of mortality. Data from a cross-sectional survey in the catchment areas of two tertiary-level paediatric hospitals in Dhaka, Bangladesh, were analyzed to identify the factors associated with the uptake of services from trained healthcare providers for under-five children with reported febrile illness. Health and demographic data were collected in a larger study of 7,865 children using structured questionnaires. Data were selected from 1,290 of these under-five children who were taken to any healthcare provider for febrile illness within two months preceding the date of visit by the study team. Certified doctors were categorized as ‘trained’, and other healthcare providers were categorized as ‘untrained’. Healthcare-seeking behaviours were analyzed in relation to these groups. A wealth index was constructed using principal component analysis to classify the households into socioeconomic groups. The odds ratios for factors associated with healthcare-seeking behaviours were estimated using logistic regression with adjustment for clustering. Forty-one percent of caregivers (n=529) did not seek healthcare from trained healthcare providers. Children from the highest wealth quintile were significantly more likely [odds ratio (OR)=5.6, 95% confidence interval (CI) 3.4-9.2] to be taken to trained healthcare providers compared to the poorest group. Young infants were more likely to be taken to trained healthcare providers compared to the age-group of 4-<5 years (OR=1.6, 95% CI 1.1-2.4). Male children were also more likely to be taken to trained healthcare providers (OR=1.5, 95% CI 1.2-1.9) as were children with decreased level of consciousness (OR=5.3, 95% CI 2.0-14.2). Disparities across socioeconomic groups and gender persisted in seeking quality healthcare for under-five children with febrile illness in urban Dhaka. Girls from poor families were less likely to access qualified medical care. To reduce child mortality in the short term, health education and behaviour-change communication interventions should target low-income caregivers to improve their recognition of danger-signs; reducing societal inequalities remains an important long-term goal

Risk behaviours associated with urethritis in prison inmates, Sindh

Objective: To identify sexual risk behaviours associated with lifetime risk of urethritis in prison inmates.Design: A cross-sectional study using a pre-designed questionnaire.SETTING: Fourteen prisons throughout the Sindh Province, Pakistan.SUBJECTS: Three thousand three hundred ninety-five prison inmates incarcerated during July, 1994.MAIN OUTCOME MEASURE: Lifetime risk of urethritis occurrence (whether or not the subject was ever affected with urethritis up to his present age)Results: Lifetime risk of urethritis occurrence in the study population was 20.8% (706/3395). The final multivariate logistic regression model indicated that risk behaviours associated with lifetime risk of urethritis in this population were \u27sexual intercourse with a female\u27 (adjusted OR = 2.18; 95% CI 1.60, 2.95), \u27multiple female sexual partners\u27 (adjusted OR = 1.67; 95% CI 1.28, 2.18) and \u27sexual intercourse with man\u27 (adjusted OR = 2.75; 95% CI 2.29, 3.31).CONCLUSION: The prevalence of urethritis in this population was very high. High prevalence of various risky sexual behaviours among inmates indicates, their unawareness as to what precautions they might take to avoid risk of acquiring STDs including HIV. The study subjects meet the characteristics of a core group of STDs transmitters and provides short window of opportunity for STD/HIV control programs to intervene, while they are in detention to reduce the risk not only for this group but also for general population

Out-of-pocket expenses borne by the users of obstetric services at government hospitals in Karachi, Pakistan

Objective: Financing health services is a challenge for health policy makers world over, especially in developing countries. Alternate mechanisms such as user fees are being proposed. However, there is a feeling that in developing countries, users of government hospitals spend appreciable personal income to obtain free services at these facilities.Methods: This study aimed to measure the extent and the factors associated with of out-of-pocket expenses borne by the users of obstetric care at government hospitals. It also aimed to determine willingness of consumers to bear out of pocket expenses. It was conducted in three government hospitals in Karachi.Results: Seven hundred cases were registered in the study. Sixty-five percent of them had a monthly household income of less than Rupees (Rs.) 3000. Overall, users spent mean of Rs. 590 as out-of-pocket expenses for obstetric services. Of this Rs. 330 was spent on drugs and Rs. 24 on user fees. Thirty-nine percent of the patients were willing to spend out of pocket for services provided at government hospital and 39% declined to do so. Of the patients indicating willingness to spend, 98% agreed to do so for drugs.CONCLUSION: The results suggest that considerable expenses are borne out of pocket by the users of government hospitals for supposedly free services . If user fees are to be increased the government needs to provide services for which the people will pay, such as drugs, otherwise increase in this fees will simply add to financial burden on the users

Simulating Auxiliary Inputs, Revisited

For any pair $(X,Z)$ of correlated random variables we can think of $Z$ as a randomized function of $X$. Provided that $Z$ is short, one can make this function computationally efficient by allowing it to be only approximately correct. In folklore this problem is known as \emph{simulating auxiliary inputs}. This idea of simulating auxiliary information turns out to be a powerful tool in computer science, finding applications in complexity theory, cryptography, pseudorandomness and zero-knowledge. In this paper we revisit this problem, achieving the following results: \begin{enumerate}[(a)] We discuss and compare efficiency of known results, finding the flaw in the best known bound claimed in the TCC'14 paper "How to Fake Auxiliary Inputs". We present a novel boosting algorithm for constructing the simulator. Our technique essentially fixes the flaw. This boosting proof is of independent interest, as it shows how to handle "negative mass" issues when constructing probability measures in descent algorithms. Our bounds are much better than bounds known so far. To make the simulator $(s,\epsilon)$-indistinguishable we need the complexity $O\left(s\cdot 2^{5\ell}\epsilon^{-2}\right)$ in time/circuit size, which is better by a factor $\epsilon^{-2}$ compared to previous bounds. In particular, with our technique we (finally) get meaningful provable security for the EUROCRYPT'09 leakage-resilient stream cipher instantiated with a standard 256-bit block cipher, like $\mathsf{AES256}$.Comment: Some typos present in the previous version have been correcte