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Many doctors will allow pregnant women with thrombocytopenic purpura to try and deliver their baby vaginally instead of via a cesarean section. Thrombocytopenic purpura is characterized by low blood levels of platelets, and it leads to excessive bleeding.

Some cases of fractured clavicles or Erb's palsy after birth may not be associated with any known risk factors, and might not be preventable. Erb's palsy is nerve damage distinguished by limited arm movements. Fifty-one infants with Erb's palsy and 236 with clavicle fractures were investigated. Difficult delivery of the shoulder called shoulder dystocia, and abnormally heavy infant weight were associated with these traumas. However, more than half of the fractures and 25% of the cases of Erb's palsy had no known risk factors or apparent cause for these birth injuries.

Byline: David Peleg Author Affiliation: Department of Obstetrics and Gynecology, University of Iowa Hospitals and Clinics 200 Hawkins Dr., Iowa City, IA 52242-1080

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/S0002-9378(97)80049-X Byline: David Peleg Author Affiliation: Department of Obstetrics and Gynecology, University of Iowa Hospitals and Clinics, 200 Hawkins Dr. Iowa City, IA 52242-1080

How do the social graphs of Technical Program Committeesof conferences look like? and how can studying these social graphs help us to decide whether there is a bias in paper selection processes for conferences? This work empirically studies the structure of program committees’ social graphs, their unique structure and characteristics, and examines the existence of a bias in favor of the collaborators of the program committee members. Specifically, it checks whether a paper written by a past collaborator of a program committee member is more likely to be accepted to the conference (which may be interpreted as indicating a bias on behalf of the program committee members). Twelve ACM/IEEE conferences over several years were studied, and the social network of each annual meeting of a conference was constructed. The vertex set of such a network consists of the program committee members and the authors of the papers accepted to the meeting, and two researchers are neighbors in the network if they were collaborators(namely, have co-authored a paper) prior to the meeting. For each meeting network, the coverageof the program committee in the network, namely, the ratio between the number of authors that are collaborators of the program committee and the total number of the authors-vertices of the meeting, was calculated. The coverage of the real meeting’s social networks was compared to the coverage in artificial meetings. A program committee is viewed as coverage biasedif its coverage is significantly higher than that of corresponding artificial meetings of the conference. Our findings show that, although there are some coverage biased program committees, for most conferences the coverage in the real meetings is the same as, and sometimes lower than, that of the artificial ones, indicating that on average there is probably no bias in favor of papers written by collaborators of the program committee members for these high-quality conferences.

The signal-to-interference & noise ratio (SINR) model is one of the most commonly studied physical (or fading channel) models for wireless networks. We survey some recent studies aiming at achieving a better understanding of the SINR model and its structural properties and developing efficient design algorithms and communication protocols for it.

This paper considers a probabilistic local polling process, examines its properties, and proposes its use in the context of distributed network protocols for achieving consensus. The resulting consensus algorithm is very simple and lightweight, yet it enjoys some desirable properties, such as proportionate agreement (namely, reaching a consensus value of one with probability proportional to the number of ones in the inputs), resilience against dynamic link failures and recoveries, and (weak) self-stabilization. The paper also investigates the maximum influence of small sets and establishes results analogous to those obtained for the problem in the deterministic polling model.

Abstract.: Traditional approaches to network design separate the issues of designing the network itself and designing its management and control subsystems. This paper proposes an approach termed routing-oriented network design, which is based on designing the network topology and its routing scheme together, attempting to optimize some of the relevant parameters of both simultaneously. This approach is explored by considering the design of communication networks supporting efficient routing in the special case of points located in the Euclidean plane. The desirable network parameters considered include low degree and small number of communication links. The desirable routing parameters considered include small routing tables, small number of hops and low routing stretch. Two rather different schemes are presented, one based on direct navigation in the plane and the other based on efficient hierarchical tree covers. On a collection of n sites with diameter D, these methods yield networks with a total of communication links and some bounds on the degree, coupled with routing schemes with constant routing stretch, memory bits per vertex and routes with at most or hops.

This paper considers an enhancement to the arrow distributed directory protocol, introduced in [8]. The arrow protocol implements a directory service, allowing nodes to locate mobile objects in a distributed system, while ensuring mutual exclusion in the presence of concurrent requests. The arrow protocol makes use of a minimum spanning treeTmof the network, selected during system initialization, resulting in a worst-case overhead ration of (1+ stretch(Tm))/2. However, we observe that the arrow protocol is correct communicating over any spanning tree Tof G. We show that the worst-caseoverhead ratio is minimized by the minimum stretch spanning treeand that the problem cannot be approximated within a factor better than (1+5)/2, unless P=NP. In contrast, other trees may be more suitable if one is interested in the average-casebehavior of the network. We show that in the case where the distribution of the requests is fixed and known in advance, the expected communication is minimized using the minimum communication cost spanning tree(MCT). It is shown that the resulting MCT problem is a restricted case for which one can find a tree Tover which the communication cost of the arrow protocol is at most 1.5 times the expected communication cost of an optimal protocol. We also show that even if the distribution of the requests is not fixed, or not known to the protocol in advance, then if the adversary is oblivious, one may use probabilistic approximation of metric space [2, 3] to ensure an expected overhead ratio of O(lognloglogn) in general and an expected ratio of O(logn) in the case of constant dimension Euclidean graphs.

Abstract.: We consider the task of assigning distinct labels to nodes of an unknown anonymous network in a distributed manner. A priori, nodes do not have any identities, except for one distinguished node, called the source, and do not know the topology or the size of the network. They execute identical algorithms, apart from the source which plays the role of a leader and starts the labeling process. Our goal is to assign short labels, as fast as possible. The quality of a labeling algorithm is measured by the range from which the algorithm picks the labels, or alternatively, the length of the assigned labels. Natural efficiency measures are the time, i.e., the number of rounds required for the label assignment, and the message and bit complexities of the label assignment protocol, i.e., the total number of messages (resp., bits) circulating in the network. We present label assignment algorithms whose time and message complexity are asymptotically optimal and which assign short labels. On the other hand, we establish inherent trade-offs between quality and efficiency for labeling algorithms.

This article considers informative labeling schemes for graphs. Specifically, the question introduced is whether it is possible to label the vertices of a graph with short labels in such a way that the distance between any two vertices can be inferred from inspecting their labels. A labeling scheme enjoying this property is termed a proximity-preserving labeling scheme. It is shown that, for the class of n-vertex weighted trees with M-bit edge weights, there exists such a proximity-preserving labeling scheme using O(M log n + log²n) bit labels. For the family of all n-vertex unweighted graphs, a labeling scheme is proposed that using O(log² n · κ · n^1/κ) bit labels can provide approximate estimates to the distance, which are accurate up to a factor of $\sqrt{8\kappa }.$ In particular, using O(log³n) bit labels, the scheme can provide estimates accurate up to a factor of $\sqrt{2 \log n}$. (For weighted graphs, one of the log n factors in the label size is replaced by a factor logarithmic in the network's diameter.) © 2000 John Wiley & Sons, Inc. J Graph Theory 33: 167–176, 2000

As communication networks grow, existing fault handling tools that involveglobalmeasures such as global time-outs or reset procedures become increasingly unaffordable, since their cost grows with the size of the network. Rather, for a fault handling mechanism to scale to large networks, its cost must depend only on the number of failed nodes (which, thanks to today's technology, grows much more slowly than the networks). Moreover, it should allow the nonfaulty regions of the networks to continue their operation even during the recovery of the faulty parts. This paper introduces the conceptsfault localityandfault-locally mendableproblems, which are problems for which there are correction algorithms (applied after faults) whose cost depends only on the (unknown) number of faults. We show thatanyinput-output problem is fault-locally mendable. The solution involves a novel technique combining data structures and “local votes” among nodes, which may be of interest in itself.

Objective: To identify the significant predictors of cesarean delivery after prelabor rupture of membranes (PROM) at term.

Objective: To compare the outcome of subsequent delivery in women with a history of a third- or fourth-degree laceration with outcomes in women without such a history.

Hematologic malignancy complicating pregnancy is rare. No one person can boast extensive experience. Although the role of the hematologist/oncologist is to observe the cancer, the obstetrician is responsible for the pregnancy. Important decisions by the patient need to be made based on medical, ethical, religious, and other personal issues. Proper informed consent requires a comprehensive review of these issues and must involve all caregivers and family members.

This paper is concerned with the solvability of the problem of processor renaming in unreliable, completely asynchronous distributed systems. Fischer et al. prove in [8] that “nontrivial consensus” cannot be attained in such systems, even when only a single, benign processor failure is possible. In contrast, this paper shows that problems of processor renaming can be solved even in the presence of up to t < n/2 faulty processors, contradicting the widely held belief that no nontrivial problem can be solved in such a system. The problems deal with renaming processors so as to reduce the size of the initial name space. When only uniqueness of the new names is required, we present a lower bound of n + 1 on the size of the new name space, and a renaming algorithm that establishes an upper bound on n + t. If the new names are required also to preserve the original order, a tight bound of 2′(n - t + 1) - 1 is obtained.

To determine the characteristics and long-term outcome of women succeeding or failing expectant management of ectopic pregnancy (EP).

To test the effectiveness of laparoscopic intratubal methotrexate (MTX) injection or salpingostomy in the treatment of ectopic pregnancy (EP).

This article presents a fast distributed algorithm to compute a smallk-dominating setD(for any fixedk) and to compute its induced graph partition (breaking the graph into radiuskclusters centered around the vertices ofD). The time complexity of the algorithm isO(klog*n). Smallk-dominating sets have applications in a number of areas, including routing with sparse routing tables, the design of distributed data structures, and center selection in a distributed network. The main application described in this article concerns a fast distributed algorithm for constructing a minimum-weight spanning tree (MST). On ann-vertex network of diameterd, the new algorithm constructs an MST in time, improving on previous results.

This paper deals with the problem of maintaining a distributed directory server, that enables us to keep track of mobile users in a distributed network. The paper introduces the graph-theoretic concept of regional matching, and demonstrates how finding a regional matching with certain parameters enables efficient tracking. The communication overhead of our tracking mechanism is within a polylogarithmic factor of the lower bound.

Summary.:  A quorum system is a collection of sets (quorums) every two of which intersect. Quorum systems have been used for many applications in the area of distributed systems, including mutual exclusion, data replication and dissemination of information. In this paper we introduce a general class of quorum systems called Crumbling Walls and study its properties. The elements (processors) of a wall are logically arranged in rows of varying widths. A quorum in a wall is the union of one full row and a representative from every row below the full row. This class considerably generalizes a number of known quorum system constructions. The best crumbling wall is the CWlog quorum system. It has small quorums, of size O(lg n), and structural simplicity. The CWlog has optimal availability and optimal load among systems with such small quorum size. It manifests its high quality for all universe sizes, so it is a good choice not only for systems with thousands or millions of processors but also for systems with as few as 3 or 5 processors. Moreover, our analysis shows that the availability will increase and the load will decrease at the optimal rates as the system increases in size.

The problem of efficient packet routing is central to the area of communication networks. The special case of permutationpacket routing has been extensively studied in the past. While optimal algorithms for permutation routing exist, they do not ‘scale up’ to give optimal solutions for the general case. Using a novel technique we obtain an optimal algorithm for the general packet routing problem.

This paper presents deterministic sublinear-time distributed algorithms for network decomposition and for constructing a sparse neighborhood cover of a network. The latter construction leads to improved distributed preprocessing time for a number of distributed algorithms, including all-pairs shortest paths computation, load balancing, broadcast, and bandwidth management.

A 23 year old woman, who was known to be in remission from thymic carcinoma, presented in her first trimester. She had previously been treated with radiation and chemotherapy. Her pregnancy was complicated by fevcr and contractions at 30 weeks and ended with the birth of a live preterm male infant. Subsequent investigation revealed a massive relapse of her mediastinal tumor. This case reinforces the devastating consequences that pregnancy has on thymic hyperplasia. Of nine previously reported cases, five of the women died either during pregnancy or within six months and only one was alive longer than five years. Therapeutic abortion should be considered in the pregnant woman with known thymic neoplasia.

Objective:To compare 12-hour and 72-hour expectant management of premature rupture of membranes (PROM) in singleton term pregnancies.

Background: In pregnancy, vesicouterine fistulas usually are diagnosed postpartum after cesarean deliveries.

The dilemma of when to deliver preterm or growth-restricted fetuses with abnormal monitoring is faced by all those treating such patients. Current noninvasive tests for fetal well-being have relatively high false-positive rates. Cordocentesis allows the clinician to directly analyze fetal blood and determine whether the fetus is truly in distress, is suffering from aneuploidy, or is plagued by infection. However, with improved neonatal care, otherwise normal infants of birth weight greater than 1500 gm have very low morbidity and mortality rates and any delay in delivery offered by cordocentesis is probably not justified. It is in the fetus whose estimated weight is below 1500 gm that cordocentesis should be used. If the results are normal, expectant management and the administration of corticosteroids will allow for pulmonary maturation and a more favorable outcome.