The structural and sedimentological evolution of the Somali Basin : paleoceanographic interpretations

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution August 1974The paleooceanographic development of the Somali Basin in the Northwestern Indian Ocean is determined through considering the structural, evolution of the area; its influence on Neogene atmospheric and oceanic circulation as indicated in the sediment record; and variation in these circulation systems as seen in late Quaternary sediments. Chain Ridge forms the main structural element of the Somali Basin. Correlation of geophysical measurements along its topographically elevated portion with geophysical transects in the southern Somali Basin indicates that a buried portion of the Chain Ridge sector of Owen Fracture Zone extends at least to 7.5°S. In areas where crustal age may be estimated on both sides of the fracture zone either by elevation or by other methods, the sea floor to the west is at least 30 m.y. older than that to the east and may be considerably older. The trend of the fracture zone and the age of its segments control the time and direction of movement for India relative to Africa and Madagascar. In addition, they limit the number of proposed reconstructions and indicate that the Western Somali Basin is a small remaining part of the original Tethys. These constraints result in a model for the area which considers Gondwanaland dispersal in the Western Indian Ocean. The final stages of development of the Somali Basin respond with the destruction of the Tethys with the regression in northern India during Middle Miocene. Neogene sedimentation rate determinations for the Somali Basin show considerable increases between the Miocene and Recent, in spite of the fact that the basin is becoming larger and deeper. It is proposed that the dessication and subsequent elevation of the area in northern India caused by structural evolution resulted in the development of a land-sea heating contrast which drives the southwest. monsoon, and due to increased upwelling and productivity it is recorded by increased sedimentation rates in the Somali Basin. The late Quaternary sediment record of the area indicates maintenance of these large scale circulations with little change in sea surface temperature as determined from nannofossil assemblage variation, and occurrence of upwelling over a broader area as indicated by the distribution of coarse carbonate. Several significant bottom water incursions into the basin are interpreted from analyzing the total carbonate curves but their effects do not extend to the area of maximum upwelling due to depression of the CCD by high productivity.Prepared for the Office of Navai Research under Contract N00014-66-C-0241; NR 083-004, the Nationai Science Foundation under Grant 27516

Behavioural activation by mental health nurses for late-life depression in primary care: a randomized controlled trial

Background: Depressive symptoms are common in older adults. The effectiveness of pharmacological treatments and the availability of psychological treatments in primary care are limited. A behavioural approach to depression treatment might be beneficial to many older adults but such care is still largely unavailable. Behavioural Activation (BA) protocols are less complicated and more easy to train than other psychological therapies, making them very suitable for delivery by less specialised therapists. The recent introduction of the mental health nurse in primary care centres in the Netherlands has created major opportunities for improving the accessibility of psychological treatments for late-life depression in primary care. BA may thus address the needs of older patients while improving treatment outcome and lowering costs.The primary objective of this study is to compare the effectiveness and cost-effectiveness of BA in comparison with treatment as usual (TAU) for late-life depression in Dutch primary care. A secondary goal is to explore several potential mechanisms of change, as well as predictors and moderators of treatment outcome of BA for late-life depression. Methods/design: Cluster-randomised controlled multicentre trial with two parallel groups: a) behavioural activation, and b) treatment as usual, conducted in primary care centres with a follow-up of 52 weeks. The main inclusion criterion is a PHQ-9 score > 9. Patients are excluded from the trial in case of severe mental illness that requires specialized treatment, high suicide risk, drug and/or alcohol abuse, prior psychotherapy, change in dosage or type of prescribed antidepressants in the previous 12 weeks, or moderate to severe cognitive impairment. The intervention consists of 8 weekly 30-min BA sessions delivered by a trained mental health nurse. Discussion: We expect BA to be an effective and cost-effective treatment for late-life depression compared to TAU. BA delivered by mental health nurses could increase the availability and accessibility of non-pharmacological treatments for late-life depression in primary care. Trial registration: This study is retrospectively registered in the Dutch Clinical Trial Register NTR6013on August 25th 2016. © 2017 The Author(s)

Comparing Effects of Nutrients on Algal Biomass in Streams in Two Regions with Different Disturbance Regimes and with Applications for Developing Nutrient Criteria

Responses of stream algal biomass to nutrient enrichment were studied in two regions where differences in hydrologic variability cause great differences in herbivory. Around northwestern Kentucky (KY) hydrologic variability constrains invertebrate biomass and their effects on algae, but hydrologic stability in Michigan (MI) streams permits accrual of high herbivore densities and herbivory of benthic algae. Multiple indicators of algal biomass and nutrient availability were measured in 104 streams with repeated sampling at each site over a 2−month period. Many measures of algal biomass and nutrient availability were positively correlated in both regions, however the amount of variation explained varied with measures of biomass and nutrient concentration and with region. Indicators of diatom biomass were higher in KY than MI, but were not related to nutrient concentrations in either region. Chl   a and % area of substratum covered by Cladophora were positively correlated to nutrient concentrations in both regions. Cladophora responded significantly more to nutrients in MI than KY. Total phosphorus (TP) and total nitrogen (TN) explained similar amounts of variation in algal biomass, and not significantly more variation in biomass than dissolved nutrient concentrations. Low N:P ratios in the benthic algae indicated N as well as P may be limiting their accrual. Most observed responses in benthic algal biomass occurred in nutrient concentrations between 10 and 30 μg TP  l −1 and between 400 and 1000 μg TN l −1 .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42905/1/10750_2005_Article_1611.pd

Ecosystem management: A comparison of greater yellowstone and georges bank

Ecosystem management links human activities with the functioning of natural environments over large spatial and temporal scales. Our examination of Greater Yellowstone and Georges Bank shows similarities exist between human uses, administrative characteristics, and some biophysical features. Each region faces growing pressures to replace traditional extractive uses with more sustainable extractive or noncommodity uses coupled with concern about endangered species. Ecosystem management as a set of practical guidelines for making decisions under evolving expectations is far from complete, and it embodies new demands on individuals and institutions. In each system these challenges are considered relative to: the public\u27s symbolic understanding of the management challenge, ecosystem management ambiguities, information availability, information use, administrative setting, and learning capabilities of governance organizations Progress in making ecosystem management operational may occur as refinements in content and approach make it an increasingly attractive option for resource users, the public, and government officials. © 1995 Springer-Verlag New York Inc

Functional brain connectivity in electrical status epilepticus in sleep

Electrical status epilepticus in sleep (ESES) is an age-related, self-limited epileptic encephalopathy. The syndrome is characterized by cognitive and behavioral abnormalities and a specific EEG pattern of continuous spikes and waves during slow-wave sleep. While spikes and sharp waves are known to result in transient cognitive impairment during learning and memory tasks performed during the waking state, the effect of epileptiform discharges during sleep on cognition and behavior is unclear. There is increasing evidence that abnormalities of coherence, a measure of the consistency of the phase difference between two EEG signals when compared over time, is an important feature of brain oscillations and plays a role in cognition and behavior. The objective of this study was to determine whether coherence of EEG activity is altered during slow-wave sleep in children with ESES when compared to typically developing children. We examined coherence during epochs of ESES versus epochs when ESES was not present. In addition, we compared coherence during slow-wave sleep between typically developing children and children with ESES. ESES was associated with remarkably high coherences at all bandwidths and most electrode pairs. While the high coherence was largely attributed to the spikes and spike-and-wave discharge, activity between spikes and spike-and-wave discharge also demonstrated high coherence. This study indicates that EEG coherence during ESES is relatively high. Whether these increases in coherence correlate with the cognitive and behavioral abnormalities seen in children with this EEG pattern remains to be determined