Privileged communication in the psychologist–client relationship.

Determining the status of privileged communications between psychologists and clients is a complex task. There is considerable variation across states with respect to the scope of psychologist–client privilege, and several sections of state codes directly and indirectly influence its status. An analysis of state laws related to privileged communication in the psychologist–client relationship is presented and prevalent legal exceptions and trends related to client privilege are discussed. Implications for practice to assist psychologists in balancing their ethical and legal obligations also are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phosphorus fractions and adsorption characteristics in grassland soils of varied soil phosphorus status

Characterization of phosphorus (P) in soils is important both agronomically and environmentally, although the outcome may depend on the technique applied. Consequently, we evaluated fractionation and adsorption, individually and jointly, and relevant ancillary soil attributes, to determine the dominant functional characteristics of soil P in 32 fertilized temperate grassland Inceptisols classified by eight soil series, and by two soil-P index and parent material groups. Residual P was low (30.7%) and organic P (Po) prominent, 42.0% vs. 17.5% for equivalent soils in unfertilized natural ecosystems. Labile fractions comprised 6.8% inorganic P (Pi) and 9.1% Po. The proportional increase in high vs. low index soils (Morgan P > 6.0 mg l⁻¹ vs. ≤ 6.0 mg l⁻¹) was higher for Pi, and highest for labile and moderately labile fractions. Only moderately labile Pi and Po differed significantly between soils of limestone and non-limestone origin. Oxalate extractable Fe (Fe_ox) and buffering (EBC) were higher in the latter. The equilibrium P concentration (EPC) was substantially higher in the high index group, and EBC and binding energy (k) substantially lower, with no significant difference in sorption maximum (Pmax). EBC equated with weak to strong buffering in different soil series, and conformed better than k to ancillary attributes. Pmax correlated in order Al_ox > clay > OC > Fe_ox, and more broadly reflected sorption attributes than oxalate-based sorption capacity (PSC). Principal component (PC) analysis showed consistent differentiation of P fractions, mostly labile and moderately labile, in PC 1 vs. adsorption and ancillary attributes in PC 2. However, scatterplots of PC scores showed that adsorption characteristics provided better functional differentiation than P fractions for distinguishing individual soil series, which may have implications in selection and interpretation of extractants not only for environmental but also for agronomic soil-tests.     

Atomic snapshots using lattice agreement

Summary Thesnapshot object is an important tool for constructing wait-free asynchronous algorithms. We relate the snapshot object to thelattice agreement decision problem. It is shown that any algorithm for solving lattice agreement can be transformed into an implementation of a snapshot object. The overhead cost of this transformation is only a linear number of read and write operations on atomic single-writer multi-reader registers. The transformation uses an unbounded amount of shared memory. We present a deterministic algorithm for lattice agreement that usedO (log² n) operations on 2-processorTest & Set registers, plusO (n) operations on atomic single-writer multi-reader registers. The shared objects are used by the algorithm in adynamic mode, that is, the identity of the processors that access each of the shared objects is determined dynamically during the execution of the algorithm. By a randomized implementation of 2-processorsTest & Set registers from atomic registers, this algorithm implies a randomized algorthm for lattice agreement that uses an expected number ofO (n) operations on (dynamic) atomic single-writer multi-reader registers. Combined with our transformation this yields implementations of atomic snapshots with the same complexity.Cambridge Research Laboratory, Digital Equipment Corporation Hagit Attiya received the B.Sc. degreeiin Mathematics and Computer Science from the Hebrew University of Jerusalem, in 1981, the M.Sc. and Ph.D. degrees in Computer Science from the Hebrew University of Jerusalem, in 1983 and 1987, respectively. She is presently a senior lecturer at the departtment of Computer Science at the Technion, Israel Institute of Technology. Prior to this, she has been a post-doctoral research associate at the Laboratory for Computer Science at M.I.T. Her general research interests are distributed computation and theoretical computer science. More specific interests include fault-tolerance, timing-based and asynchronous algorithms. Maurice Herlihy received the A.B. degree in Mathematics from Harvard University, and the M.S. and the Ph.D. degrees in Computer Science from M.I.T. From 1984 to 1989 he was a faculty member in the Computer Science Department at Carnegie Mellon University in Pittsburgh, PA. In 1989 he joined the research staff at the Digital Equipment Corporation's Cambridge Research Laboratory in Cambridge MA. Since 1994, he has been on the faculty at the Computer Science Department at Brown University. Dr. Herlihy's research interests encompass practical and theoretical aspects of distributed and concurrent computation. Ophir achman received a B.A. in computer science from the Technion, Haifa, Israel in 1989 and M.Sc. in computer science from the Technion, Haifa, Israel, in 1992. He is now studying for a D.Sc. in computer science at the Technion. His currentarea of research is distributed computing, and in particular, asynchronous shared memory systems.This work appeared in preliminary form in proceedings ofthe 6th International Workshop on Distributed Algorithms [12]. This research was partially supported by grant No. 92-0233 from the United States-Israel Binational Science Foundation (BSF), Jerusalem, Technion V.P.R. funds — B. and G. Greenberg Research Fund (Ottawa), and the fund for the promotion of research in the TechnionPart of the work of this author was performed while visiting DEC Cambridge Research Laboratory     

Read-modify-write networks

A read-modify-write register for a set of functions F provides an operation that atomically (1) returns the variables current value v, and (2) replaces that value with f(v), where f is a function in F.A read-modify-write network is a distributed data structure that implements a concurrent, lock-free, low-contention read-modify-write register. For example, counting networks ([3]) are a family of read-modify-write networks that support atomic increments and decrements.We consider the problem of constructing read-modify-write networks for particular sets of functions. Of particular interest are the read-modify-write networks fetch&add, which add to the value an arbitrary number, and fetch&mul, which multiply the value by an arbitrary number.We identify a simple algebraic property of the function set F that requires any distributed read-modify-write implementation for F to have high latency. Any such network has sequential executions in which each token traverses a number of switching elements essentially linear in the number of processes. By contrast, there exist counting networks ([9, 18]) in which tokens traverse a logarithmic number of switches.We provide a matching upper bound for a large class of read-modify-write networks including fetch&add, fetch&mul, and related networks of interest.Received: 15 October 2002, Accepted: 15 May 2003, Published online: 6 February 2004Panagiota Fatourou: Partially supported by funds from the Program E. .E.A.E.K.II of the Greek Ministry of Education. Part of the work of theauthor was performed while at the Max-Planck Institut für Informatik,Saarbrücken, Germany, while at the Department of Computer Science,University of Toronto, Canada, and while visiting the Departmentof Computer Science, Brown University, Providence, USA.Maurice Herlihy: Partially supported by NSF grant 9912401.A preliminary version of this work appears in the Proceedings of the 15th International Symposium on DIStributed Computing, pp. 330-341, Lisbon, Portugal, October 2001. This work also appears as a brief announcement in the Proceedings of the 20th Annual ACM Symposium on Principles of Distributed Computing, Newport, Rhode Island, August 2001.     

Drying of Skim Milk: Opportunities for Reducted Steam

ABSTRACT

Research trials were carried out over a two year period in an industrial skim milk powder production plant to examine the benefits of using an in-line viscometer rather than in-line density meter to control the degree of skim milk concentration in an evaporator prior to spray drying.

It was concluded that use of an in-line viscometer significantly reduces spray drier losses, overall steam consumption, pipeline blockages and evaporator fouling in the manufacture of skim milk powder.     

Presynchronization with Double-Ovsynch improves fertility at first postpartum artificial insemination in lactating dairy cows

The objective of this study was to compare circulating progesterone (P4) profiles and pregnancies per AI (P/AI) in lactating dairy cows bred by timed artificial insemination (TAI) following Ovsynch-56 after 2 different presynchronization protocols: Double-Ovsynch (DO) or Presynch-Ovsynch (PS). Our main hypothesis was that DO would increase fertility in primiparous cows, but not in multiparous cows. Within each herd (n = 3), lactating dairy cows (n = 1,687; 778 primiparous, 909 multiparous) were randomly assigned to DO [n = 837; GnRH-7d-PGF_2α-3d-GnRH-7d-Ovsynch-56 (GnRH-7d-PGF_2α-56h-GnRH-16hTAI)] or PS (n = 850; PGF_2α-14d-PGF_2α-12d-Ovsynch-56). In 1 herd, concentrations of P4 were determined at the first GnRH (GnRH1) of Ovsynch-56 and at d 11 after TAI (n = 739). In all herds, pregnancy was diagnosed by palpation per rectum at 39 d. In 1 herd, the incidence of late embryo loss was determined at 74 d, and data were available on P/AI at the subsequent second service. Presynchronization with DO reduced the percentage of animals with low P4 concentrations (<0.50 ng/mL) at GnRH1 of Ovsynch-56 (5.4 vs. 25.3%, DO vs. PS). A lesser percentage of both primiparous and multiparous cows treated with DO had low P4 concentrations at GnRH1 of Ovsynch-56 (3.3 vs. 19.7%, DO vs. PS primiparous; and 8.8 vs. 31.9%, DO vs. PS multiparous). Presynchronization with DO improved P/AI at the first postpartum service (46.3 vs. 38.2%, DO vs. PS). Statistically, a fertility improvement could be detected for primiparous cows treated with DO (52.5 vs. 42.3%, DO vs. PS, primiparous), but only a tendency could be detected in multiparous cows (40.3 vs. 34.3%, DO vs. PS, multiparous), consistent with our original hypothesis. Presynchronization treatment had no effect on the incidence of late embryo loss after first service (8.5 vs. 5.5%, DO vs. PS). A lower body condition score increased the percentage of cows with low P4 at GnRH1 of Ovsynch-56 and reduced fertility to the TAI. In addition, P4 concentration at d 11 after TAI was reduced by DO. The method of presynchronization at first service had no effect on P/AI at the subsequent second service (34.7 vs. 36.5%, DO vs. PS). Thus, presynchronization with DO induced cyclicity in most anovular cows and improved fertility compared with PS, suggesting that DO could be a useful reproductive management protocol for synchronizing first service in commercial dairy herds.     

Threshold protocols in survivor set systems

Many replication protocols employ a threshold model when expressing failures they are able to tolerate. In this model, one assumes that no more than t out of n components can fail, which is a good representation when failures are independent and identically distributed (IID). In many real systems, however, failures are not IID, and a straightforward application of threshold protocols yields suboptimal results. Here, we examine the problem of transforming threshold protocols into survivor-set protocols tolerating dependent failures. Our main goal is to show the equivalence between the threshold model and the core/survivor set model. Toward this goal, we develop techniques to transform threshold protocols into survivor set ones. Our techniques do not require authentication, self-verification or encryption. Our results show in one case that we can transform a threshold protocol to a subset by spreading a number of processes across processors. This technique treats a given threshold algorithm as a black box, and consequently can transform any threshold algorithm. However, it has the disadvantage that the transformation is not possible for all sets of survivor sets. The second technique instead focuses on transforming voters: functions that evaluate to a value out of a set of tallied values in a replication protocol. Voters are an essential part of many fault-tolerant protocols, and we show a universal way of transforming them. With such a transformation we expect that a large number of protocols in the literature can be directly transformed with our technique. It is still an open problem, however, if the two models are equivalent, and our results constitute an important first step in this direction.     

Computation in History: Styles and Methods

Recent advances in interactive computing and file management systems help the historian fulfill his traditional function as a collector, critic, and interpreter of documents.     

Tight bounds for k-set agreement with limited-scope failure detectors

In a system with limited-scope failure detectors, there are q disjoint clusters of processes such that some correct process in each cluster is never suspected by any process in that cluster. The failure detector class S_x,q satisfies this property all the time, while ⋄S_x,q satisfies it eventually. This paper gives the first tight bounds for the k-set agreement task in asynchronous message-passing models augmented with failure detectors from either the S_x,q or ⋄S_x,q classes. For S_x,q, we show that any k-set agreement protocol that tolerates f failures must satisfy f < k + x − q if q < k and f < x otherwise, where x is the combined size of the q disjoint clusters if q < k (or the k largest, otherwise). This result establishes for the first time that the protocol of Mostèfaoui and Raynal for the S_x = S_x,1 failure detector is optimal. For ⋄S_x,q, we show that any k-set agreement protocol that tolerates f failures must satisfy if q < k and otherwise, where n + 1 is the total number of processes. We give a novel protocol that matches our lower bound, disproving a conjecture of Mostèfaoui and Raynal for the ⋄S_x = ⋄S_x,1 failure detector. Our lower bounds exploit techniques borrowed from Combinatorial Topology, demonstrating for the first time that this approach is applicable to models that encompass failure detectors.