Communication Cost for Updating Linear Functions when Message Updates are Sparse: Connections to Maximally Recoverable Codes

We consider a communication problem in which an update of the source message needs to be conveyed to one or more distant receivers that are interested in maintaining specific linear functions of the source message. The setting is one in which the updates are sparse in nature, and where neither the source nor the receiver(s) is aware of the exact {\em difference vector}, but only know the amount of sparsity that is present in the difference-vector. Under this setting, we are interested in devising linear encoding and decoding schemes that minimize the communication cost involved. We show that the optimal solution to this problem is closely related to the notion of maximally recoverable codes (MRCs), which were originally introduced in the context of coding for storage systems. In the context of storage, MRCs guarantee optimal erasure protection when the system is partially constrained to have local parity relations among the storage nodes. In our problem, we show that optimal solutions exist if and only if MRCs of certain kind (identified by the desired linear functions) exist. We consider point-to-point and broadcast versions of the problem, and identify connections to MRCs under both these settings. For the point-to-point setting, we show that our linear-encoder based achievable scheme is optimal even when non-linear encoding is permitted. The theory is illustrated in the context of updating erasure coded storage nodes. We present examples based on modern storage codes such as the minimum bandwidth regenerating codes.Comment: To Appear in IEEE Transactions on Information Theor

ARES: Adaptive, Reconfigurable, Erasure coded, atomic Storage

Atomicity or strong consistency is one of the fundamental, most intuitive, and hardest to provide primitives in distributed shared memory emulations. To ensure survivability, scalability, and availability of a storage service in the presence of failures, traditional approaches for atomic memory emulation, in message passing environments, replicate the objects across multiple servers. Compared to replication based algorithms, erasure code-based atomic memory algorithms has much lower storage and communication costs, but usually, they are harder to design. The difficulty of designing atomic memory algorithms further grows, when the set of servers may be changed to ensure survivability of the service over software and hardware upgrades, while avoiding service interruptions. Atomic memory algorithms for performing server reconfiguration, in the replicated systems, are very few, complex, and are still part of an active area of research; reconfigurations of erasure-code based algorithms are non-existent. In this work, we present ARES, an algorithmic framework that allows reconfiguration of the underlying servers, and is particularly suitable for erasure-code based algorithms emulating atomic objects. ARES introduces new configurations while keeping the service available. To use with ARES we also propose a new, and to our knowledge, the first two-round erasure code based algorithm TREAS, for emulating multi-writer, multi-reader (MWMR) atomic objects in asynchronous, message-passing environments, with near-optimal communication and storage costs. Our algorithms can tolerate crash failures of any client and some fraction of servers, and yet, guarantee safety and liveness property. Moreover, by bringing together the advantages of ARES and TREAS, we propose an optimized algorithm where new configurations can be installed without the objects values passing through the reconfiguration clients

Risk factors for non-communicable diseases in rural Uganda: a pilot surveillance project among diabetes patients at a referral hospital clinic

<0.0001) and (30.7 vs. 13%; p<0.0001) respectively. Overweight, obesity and hypertension were more prevalent in women (18.6% vs. 9.7%, 8.6% vs. 2.6%; p<0.0001, and 40.3% vs. 33%, p=0.018) respectively. CONCLUSION: This pilot project shows that use of hospital-based data is a valuable initial step in setting up surveillance systems for NCDs in Uganda. Risk factors for NCDs were both age and gender-specific and predominantly related to lifestyle. This suggests the need to design gender-sensitive prevention interventions that target lifestyle modification in this setting

TH1.1: Intra-household decision-making and sustained use of agricultural crop technologies: Evidence from smallholder women farmers in rural Uganda

This research used a mixed method approach to examine how intra-household decision-making patterns shape sustained use of crop technologies among agricultural rural households in eastern Uganda. We estimate how empowerment in decision making, measured using indicators drawn from the project level Women's Empowerment in Agriculture Index mediates sustained use of improved crop varieties. Further, spousal differences in decision-making power and technology use are examined. The results indicate that both men and women use diverse improved crop varieties for different purposes. Overall, we observe differential patterns of use of improved crop varieties with a high proportion of women reporting sustained use of food-related crops while a high proportion of men report income crops. There was a significant association between level of decision making power and sustained use of improved crops by men and women. Women with higher level of participation in decision making power have more sustained use of improved varieties for the main crops grown. Note to be taken that a gender gap still exists in access to improved varieties with men having 6years of use on average as compared to 5 years for women. We also find significant differences between men and women in the same household in their rating of the distribution and extent of involvement in key decisions with less agreement (and mis-attribution) observed among men and women in decision-making scores. Women decision makers tend to allocate themselves higher scores than was assigned to them by their counterparts. We conclude that women's empowerment in decision making has potential to contribute to closing the gender gap in sustained use of agricultural technologies. We therefore need to be more intentional about women's participation, decision making and agency in development interventions if we are to achieve greater impacts in sustained use of agricultural technologies towards better livelihoods

Clues For Genetic Anticipation In Multiple Endocrine Neoplasia Type 1

CONTEXT: Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant hereditary disease caused by the loss of function of the MEN1 gene, a tumor-suppressor gene that encodes the protein menin. It is characterized by the occurrence of primary hyperparathyroidism (pHPT), duodenopancreatic neuroendocrine tumors (dpNET), pituitary tumors (PIT), adrenal adenomas, and bronchopulmonary (bp-NET), thymic, and gastric neuroendocrine tumors. More insight into factors influencing the age-related penetrance of MEN1 manifestations could provide clues for more personalized screening programs. OBJECTIVE: To investigate whether genetic anticipation plays a role in the largest known MEN1 families in the Netherlands. METHODS: All Dutch MEN1 families with ≥ 10 affected members in ≥ 2 successive generations were identified. Age at detection of the different MEN1-related manifestations were compared among generations using regression analyses adjusted for competing risks. To correct for the beneficial effect of being under surveillance, manifestations occurring during surveillance were also separately compared. RESULTS: A total of 152 MEN1 patients from 10 families were included. A significantly decreased age at detection of pHPT, dpNET, PIT, and bp-NET was found in successive generations (P < 0.0001). Adjusted analyses led to the same results. CONCLUSIONS: These results suggest the presence of genetic anticipation. However, due to a risk of residual bias, the results must be interpreted with caution. After independent validation in other cohorts and further translational research investigating the molecular mechanisms explaining this phenomenon in MEN1, the results might add to future, more personalized, screening protocols and earlier screening for future generations of MEN1 patients

Should health care professionals encourage living kidney donation?

Living kidney donation provides a promising opportunity in situations where the scarcity of cadaveric kidneys is widely acknowledged. While many patients and their relatives are willing to accept its benefits, others are concerned about living kidney programs; they appear to feel pressured into accepting living kidney transplantations as the only proper option for them. As we studied the attitudes and views of patients and their relatives, we considered just how actively health care professionals should encourage living donation. We argue that active interference in peoples’ personal lives is justified - if not obligatory. First, we address the ambiguous ideals of non-directivity and value neutrality in counselling. We describe the main pitfalls implied in these concepts, and conclude that these concepts cannot account for the complex reality of living donation and transplantation. We depict what is required instead as truthful information and context-relative counselling. We then consider professional interference into personal belief systems. We argue that individual convictions are not necessarily strong, stable, or deep. They may be flawed in many ways. In order to justify interference in peoples’ personal lives, it is crucial to understand the structure of these convictions. Evidence suggests that both patients and their relatives have attitudes towards living kidney donation that are often open to change and, accordingly, can be influenced. We show how ethical theories can account for this reality and can help us to discern between justified and unjustified interference. We refer to Stephen Toulmin’s model of the structure of logical argument, the Rawlsian model of reflective equilibrium, and Thomas Nagel’s representation of the particularistic position

Starting a Crossover Kidney Transplantation Program in The Netherlands: Ethical and Psychological Considerations

On April 15th, 2003, the first crossover kidney transplantation took place in The Netherlands. In September of the same year, a national database was established to facilitate kidney exchange between two donor-recipient couples. During 2004, kidneys from living donors will be exchanged between the seven university medical centers in The Netherlands. One of the conditions for successfully implementing this program was the need to address the ethical and psychologic implications involved. In this article we will discuss the ethical and psychologic considerations that are accompanying the practical preparations for the first Dutch crossover transplantation program. We identified five topics of interest: the influence of &quot;donation by strangers&quot; on the motivation and willingness of donor-patient couples, the issue of anonymity, the loss of the possibility of &quot;medical excuses&quot; for unwilling donors, the view that crossover is a first step to commercial organ trade, and the interference with existing organ donation programs. We concluded that whether viewed separately or in combination, these issues do not impede the efficient organization of a crossover program or raise worrying ethical issues. Key Words: Ethics, psychology, crossover transplantation, kidney exchange program. 2004;78: 194 -197) T he Netherlands has a population of 16 million. Approximately 375 to 425 kidneys per year are transplanted from cadaver donors. In addition to cadaver transplants, approximately 200 kidneys from living donors were transplanted during 2003. Although the growing number of available living donors helps prevent the waiting lists from growing further, there are not enough kidneys available to help the 1,300 patients already on the waiting list. After starting dialysis, kidney patients have an average waiting time of 4 years before a kidney becomes available. In the meantime, their health status declines. Currently, the mortality rate of patients on dialysis is approximately 20% per year (1). (Transplantation Living organ donation by family or friends offers an opportunity to reduce the long waiting lists. However, in a third of these cases, the transplantation cannot take place because of ABO incompatibility or donor-specific sensitization (2). A crossover transplantation program offers new hope. The program provides a lifesaving opportunity when a donor cannot give his or her kidney to his or her recipient. If another donor-recipient couple experiences the same problem, the kidneys can be exchanged. In South Korea, such a crossover kidney exchange program has been operating successfully for more than 10 years (3). The United States also has experience with &quot;kidney swapping&quot; (4). In Europe, however, crossover transplantations have been attempted only once in Switzerland, in Romania, and in Rotterdam. This conservative European attitude is in part explained by concerns surrounding the ethical and psychologic implications of crossover transplantation. When a crossover program was initiated in The Netherlands, it was agreed that these concerns should be addressed. A multidisciplinary research effort was conducted to determine the most prominent psychologic and ethical issues that surround crossover kidney exchange and to propose practical solutions. We identified five topics of interest: (1) the influence of &quot;donation by strangers&quot; on the motivation and willingness of donor-patient couples; (2) the issue of anonymity; (3) the loss of the possibility of &quot;medical excuses&quot; for unwilling donors; (4) the view that crossover might be the first step to commercial organ trade; and (5) the interference with existing organ donation programs. Next we describe these five topics in detail and suggest practical solutions. Living Organ Donation by Strangers When discussing the ethical and psychologic issues of a crossover transplantation program, a prominent issue is the possibility of a difference in motivation and willingness of kidney donors and recipients compared with the attitudes of those involved in a direct living donation program. At first glance, crossover donation between two couples is not significantly different from direct living kidney donation. The motivation of the donor is the same: helping a friend or a family member by giving a kidney. The result for the patient is equivalent as well: He or she receives the much needed organ. Furthermore, the medical impact for the four people involved is the same as for the two direct living kidney donors. Psychologically, however, it might matter for those involved whethe

Pleistocene Tectono-magmato-volcanic events recorded east of Mayotte - insights for the ongoing seismo-volcanic crisis

The offshore eastern Mayotte area has been extensively studied since the outbreak of the seismo-volcanic crisis in May 2018. Several oceanographic surveys have been carried out by REVOSIMA – https://doi.org/10.18715/MAYOTTE.REVOSIMA (MAYOBS cruises -https://doi.org/10.18142/291) for monitoring purpose, or for academic research (SISMAORE - https://doi.org/10.17600/18001331 and SCRATCH cruises - https://doi.org/10.17600/18002274). They offer a complete coverage of the eastern slope and abyssal plain with multibeam bathymetry and backscatter imagery, sub-bottom profiler (SBP), and several sediment cores. This set of data offers the opportunity to describe the morphology of the area and details the first tens of meters of the sedimentary succession on the abyssal plain.We discover several features including faults, domes and massive chaotic deposits that developed or occurred during Quaternary in the vicinity of the new Fani Maore Volcano. Domes are interpreted as forced folds related to the intrusion of a large sill at depth. The main fault crossing the largest forced fold is a succession of en-echelon segments with vertical throws of up to 8 meters and a preferential N130° strike compatible with the present day regional dextral context. Analysis of the SBP profiles reveals that faulting and doming associated to sill intrusion occurred simultaneously, and together with the deposition of two massive (several km3) and chaotic lobes at the foot of the Mayotte slope. Sediment cores collected over or close to the massive deposits indicate a mixed bioclastic-volcanoclastic content with a large amount of pumices, whose aspect and chemical composition are identical to volcanic edifices located on the upper slope (Horseshoe Volcano) or onshore (Petite-Terre). Backscatter imagery also reveals streaks that cover the lobes and trace back to the same upper slope area. Analysis of bioclasts from a core catcher stopped in the upper part of the deposit shows a large variety of foraminifers, shells fragments, with a little proportion originating from the upper-slope and shelf. We propose that these massive lobe deposits might have occurred as the pumice-dominated material ejected at HV or PT flows downslope, thus reworking and incorporating a substantial amount of hemipelagic deposits along the slope and over the abyssal plain. These observations suggests that a tectono-magmato-volcanic event occurred during recent geological time (Late Pleistocene according to early estimations). At least one comparable set of similar and synchronous features appears on our dataset thus implying the occurrence of a similar event, earlier in the Pleistocene. The correlations between these events and the activity at HV and PT volcanic centers are critical, as it would provide a recurring scenario to compare with present day seismo-volcanic crisis at Mayotte.This work is funded by REVOSIMA, ANR funded COYOTES project, and internal BRGM Project PDEV MAYOTTE.COmores & maYotte : vOlcanisme, TEctonique et Sismicit

Clientelism as civil society? Unpacking the relationship between clientelism and democracy at the local level in South Africa

This article, building on analyses from the global south, attempts to reframe democratic expectations by considering where previously maligned practices such as clientelism may hold moments of democracy. It does so by comparing the theory of civil society with that of clientelism, and its African counterpart neo-patrimonialism. It argues that clientelism as civil society may fulfil democratic tasks such as holding the (local) state accountable, strengthening civil and political liberties and providing channels of access for previously marginalised groups. Clientelism is not necessarily a reflection of imposed power relations but, at times, can demonstrate a conscious political strategy, to generate development, on the part of its protagonists.IS