Morphology, biostratigraphy, and evolution of PliocenePleistocene diatoms Proboscia barboi..

Proboscia barboi and Proboscia curvirostris are two important diatom biostratigraphic markers from the high latitudes of the North Pacific and North Atlantic Oceans, dating back to the Pliocene-Pleistocene time. This study analyzes the biostratigraphic events and describes the morphology of P. barboi and P. curvirostris, particularly the morphologic variations of the latter species, based on observations of samples of Core U1340A from the IODP Expedition 323 in the Bering Sea. In Site U1340, the First Occurrence of P. curvirostris is observed at 1.52Ma and its First Common Occurrence at 1.39Ma, where morphologic variations were found abundantly. The Last Occurrence of P. curvirostris was found at 0.33Ma, while P. barboi's Last Occurrence is found at 0.67Ma. Based on the morphological similarity and known biostratigraphic distribution, previous authors have assumed that P. curvirostris descends from P. barboi, although this hypothesis is still in debate. At 1.39Ma P. curvirostris shows an increased size and thickness, which is typical of P. barboi, and some specimens display an incipient structure characteristic of P. curvirostris - the secondary spine. This morphology is intermediate between the two species and suggests an evolutionary transition from P. barboi to P. curvirostris. However, P. curvirostris already existed since 1.9Ma in the subarctic indicating that its speciation happened much earlier than 1.39Ma. Furthermore, since P. barboi co-occurs with P. curvirostris in the North Pacific, this evolutionary process was cladogenetic. Besides being evidence for a phylogenetic relationship, the abundant occurrence of intermediate forms at 1.39Ma may constitute a bioevent for a short time interval in the Bering Sea.info:eu-repo/semantics/publishedVersio

A method for determining the radius of an open cluster from stellar proper motions

We propose a method for calculating the radius of an open cluster in an objective way from an astrometric catalogue containing, at least, positions and proper motions. It uses the minimum spanning tree (hereinafter MST) in the proper motion space to discriminate cluster stars from field stars and it quantifies the strength of the cluster-field separation by means of a statistical parameter defined for the first time in this paper. This is done for a range of different sampling radii from where the cluster radius is obtained as the size at which the best cluster-field separation is achieved. The novelty of this strategy is that the cluster radius is obtained independently of how its stars are spatially distributed. We test the reliability and robustness of the method with both simulated and real data from a well-studied open cluster (NGC 188), and apply it to UCAC4 data for five other open clusters with different catalogued radius values. NGC 188, NGC 1647, NGC 6603 and Ruprecht 155 yielded unambiguous radius values of 15.2+/-1.8, 29.4+/-3.4, 4.2+/-1.7 and 7.0+/-0.3 arcmin, respectively. ASCC 19 and Collinder 471 showed more than one possible solution but it is not possible to know whether this is due to the involved uncertainties or to the presence of complex patterns in their proper motion distributions, something that could be inherent to the physical object or due to the way in which the catalogue was sampled.Comment: 12 pages including 14 figures and 1 table. Accepted for publication in MNRA

The miRNAome of the postpartum dairy cow liver in negative energy balance

peer-reviewedBackground: Negative energy balance (NEB) is an altered metabolic state in high yielding cows that occurs during the first few weeks postpartum when energy demands for lactation and maintenance exceed the energy supply from dietary intake. NEB can, in turn, lead to metabolic disorders and to reduced fertility. Alterations in the expression of more than 700 hepatic genes have previously been reported in a study of NEB in postpartum dairy cows. miRNAs (microRNA) are known to mediate many alterations in gene expression post transcriptionally. To study the hepatic miRNA content of postpartum dairy cows, including their overall abundance and differential expression, in mild NEB (MNEB) and severe NEB (SNEB), short read RNA sequencing was carried out. To identify putative targets of differentially expressed miRNAs among differentially expressed hepatic genes reported previously in dairy cows in SNEB computational target identification was employed. Results: Our results indicate that the dairy cow liver expresses 53 miRNAs at a lower threshold of 10 reads per million. Of these, 10 miRNAs accounted for greater than 95% of the miRNAome (miRNA content). Of the highly expressed miRNAs, miR-122 constitutes 75% followed by miR-192 and miR-3596. Five out of thirteen let-7 miRNA family members are also among the highly expressed miRNAs. miR-143, down-regulated in SNEB, was found to have 4 putative up-regulated gene targets associated with SNEB including LRP2 (low density lipoprotein receptor-related protein 2), involved in lipid metabolism and up-regulated in SNEB. Conclusions: This is the first liver miRNA-seq profiling study of moderate yielding dairy cows in the early postpartum period. Tissue specific miR-122 and liver enriched miR-192 are two of the most abundant miRNAs in the postpartum dairy cow liver. miR-143 is significantly down-regulated in SNEB and putative targets of miRNA-143 which are up-regulated in SNEB, include a gene involved in lipid metabolism.Teagasc Walsh Fellowship Programm

PREPARATION OF FERROUS SULFATE MICROCAPSULES AS A SUSTAINED RELEASE DOSAGE FORMS

Objective: The main purpose of this study was to optimize the different methods for the preparation for the preparation sustained release microencapsulated ferrous sulfate as a solid dosage form. Methods: Ferrous sulfate was prepared as microcapsules using three microencapsulation methods. Complex coacervation, aqueous colloidal polymer dispersions, and solvent removal methods were used to prepare various formulas with different coating agents (acacia, gelatin, sodium alginate and ethylcellulose). The formation and texture characteristics, entrapment efficiency, release profiles, particle size and storage stability of ferrous microcapsules were evaluated in this study. Results: The encapsulation efficiency and hardening varied considerably among these three preparation methods. Encapsulation of ferrous sulfate by complex coacervation with a coating agent (gelatin and acacia) showed problems in hardening and poor encapsulation efficiency. However, ferrous sulfate when coated by sodium alginate at 1:1 (coat: core) ratio using aqueous colloidal polymer dispersion method showed acceptable encapsulation efficiency (67%±0.1). Moreover, ferrous sulfate/sodium alginate microcapsules hardened successively when dropping into CaCl2 solution (2% w/v). A same hardening features and values of encapsulation efficiency (68 %±0. 6) Were obtained by solvent removal methods. Especially, after tween 80 and carboxyl methyl cellulose were added to the aqueous phase in the process of coating with ethylcellulose. However, sustained release microcapsules were produced by aqueous colloidal polymer dispersion method. The sustained-release sodium alginate/ferrous sulfate was stable for 30 d in both refrigeration and room temperature. Conclusion: The aqueous polymer dispersion gave sustain release microcapsules which were uniform, hard and stable during storage at both room temperature and refrigeration. Keywords: Ferrous sulfate, Microcapsules, Complex coacervation, Aqueous colloidal, Polymer dispersion, Solvent remova

Risk of Adverse Perinatal Outcomes in Dizygotic Twins After IVF Pregnancies: A Systematic Review

Background: Since the birth of the first test tube baby, 25 years ago, more than three million babies have been born using assisted reproductive technologies (ART). Twin births by way of ART represent 20-30% of U.S. and European births, as compared to only 1% of natural births. The purpose of this study is to investigate the risk of adverse perinatal outcomes in ART dizigotic twins, compared with non-ART twins. Method: A review of the medical literature available in Pub Med, EBM review, the National Clinical Trials Registry and CINAHL databases. The search was limited to English language sources between 2000 and 2010. Three cohort studies were identified for the final systematic review. The GRADE tool was used to evaluate the evidence. Results: The three cohort studies found no higher risk of low birth weight in ART twins after stratification for maternal age and parity. Birth weight discordance and mortality rates showed similar result as low birth weight. Two of the studies found an increased risk of hospitalization and neonatal intensive care unit admissions and maintained this result after stratification for maternal factors. One study found a higher risk of prematurity in twins conceived by in vitro fertilization; no such association was found in the other study. Conclusion: A review of the evidence found an increased risk of adverse perinatal outcome in twins conceived by in vitro fertilization, compared with twin not conceived by in vitro fertilization. However, no statistically significance differences were found after stratification for maternal confounders, with the exception of hospital and NICU admission. The grade for all outcomes was moderate

Project Management in Product Development: Toward a Framework for Targeted Flexibility

As a discipline, project management has been accused of having lost its relevance for innovative initiatives because it emphasizes planning and control over the flexibility and learning-based strategies that are needed to succeed under uncertainty. Several authors therefore recommend adaptive project management practices - sometimes named “targeted flexibility” - that respond to project characteristics commonly found in innovation, namely novelty, complexity, speed and - as a result - uncertainty. This paper investigates how this proposed adaptation of project management occurs in a context with high levels of novelty that organizes work in projects and needs to accommodate projects of different pace, complexity and innovativeness: product development in small and medium enterprises that do research and development work in the same organizational unit. Results of a literature review and two exploratory studies, covering a total of 8 companies with multiple projects each, are presented. Implications for a future framework for targeted flexibility are developed, leading to the identification of the following needs for project management: (1) better understanding of the many ways in which project management impacts exploration and exploitation activities, (2) improved attention for the currently poorly supported pre-project and early initiation stages, (3) a shift of focus from monitoring against plans toward monitoring against achieved learning, and (4) the formulation of transition paths from current new product development practice to higher project management maturity

Heuristics in Decision Making

Heuristics are simple rules of thumbs for problem solving that follow a logic that is quite different from consequential logic. They have long been regarded, as an inferior technique for decision making that is the source of irrational decision behavior. Recently, decision making researchers have demonstrated that some heuristics are highly efficient and can compete with complex decision models in some application domains. This paper explores the different streams of research, summarizes the state of the art decision making model, and discusses its implications for complex decisions in engineering and technology management