Rapid ecosystem response to abrupt climate changes during the last glacial period in western Europe, 40-16 ka

We present a high-resolution and independently dated multiproxy lake sediment record from the paleolake at Les Echets in southeastern France that displays synchronous changes in independent limnic and terrestrial ecosystem proxies, in concert with millennial-scale climate oscillations during the last glacial period. Distinct lake-level fluctuations, low lake organic productivity, and open, treeless vegetation indicate cold and dry conditions in response to Heinrich events. Alternating phases of higher and low lake organic productivity, stratified surface waters and long-lasting lake ice cover, decreased or increased catchment erosion, and tree-dominated or herb-dominated vegetation resemble Dansgaard-Oeschger interstadial-stadial variability. Transitions between different ecological states occurred in as little as 40-230 yr and seem to have been controlled by the position of the Polar Front. Ecosystem response after 30 ka suggests that local climate conditions became more important. Our results demonstrate that all parts of the terrestrial system responded to the abrupt and dramatic climatic changes associated with Dansgaard-Oeschger and Heinrich events, and that regional factors modulated ecosystem response.

40 years is an awful long time

ABSTRACT: Older people who are caring for their adult sons and daughters with disabilities are under tremendous stress because they may suffer health problems themselves; have financial problems due a lifetime of caring; may have to care on their own due to the death of their spouse; worry about the future care of their child; and may feel uncomfortable approaching professionals for help. Professionals working with these families need to take contextual pressures into consideration when planning intervention. Twenty-nine parents of 27 adults with intellectual and/or developmental disabilities (including autism) were asked about present care and service arrangements, health issues, family support, and “futures planning.” The research reported here identifies complex networks of relationships. Virtual absence of structured futures planning was one of the key issues. Recommendations are made for professionals working in this field.

Inward rectifier potassium channels in the HL-1 cardiomyocyte-derived cell line.

HL-1 is a line of immortalized cells of cardiomyocyte origin that are a useful complement to native cardiomyocytes in studies of cardiac gene regulation. Several types of ion channel have been identified in these cells, but not the physiologically important inward rectifier K(+) channels. Our aim was to identify and characterize inward rectifier K(+) channels in HL-1 cells. External Ba(2+) (100?µM) inhibited 44?±?0.05% (mean?±?s.e.m., n?=?11) of inward current in whole-cell patch-clamp recordings. The reversal potential of the Ba(2+)-sensitive current shifted with external [K(+)] as expected for K(+)-selective channels. The slope conductance of the inward Ba(2+)-sensitive current increased with external [K(+)]. The apparent Kd for Ba(2+) was voltage dependent, ranging from 15?µM at -150 ?mV to 148?µM at -75 ?mV in 120 ?mM external K(+). This current was insensitive to 10?µM glybenclamide. A component of whole-cell current was sensitive to 150?µM 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS), although it did not correspond to the Ba(2+)-sensitive component. The effect of external 1 mM Cs(+) was similar to that of Ba(2+). Polymerase chain reaction using HL-1 cDNA as template and primers specific for the cardiac inward rectifier K(ir)2.1 produced a fragment of the expected size that was confirmed to be K(ir)2.1 by DNA sequencing. In conclusion, HL-1 cells express a current that is characteristic of cardiac inward rectifier K(+) channels, and express K(ir)2.1 mRNA. This cell line may have use as a system for studying inward rectifier gene regulation in a cardiomyocyte phenotype.

Ultrafast Low-Loss 40-70 GHz SPST Switch

The design and characterizations of an ultrafast single-pole single-throw (SPST) absorptive differential switch are presented. The switch exhibits low insertion loss less than 1 dB, and isolation better than 16 dB from 40 to 70 GHz. Sub-nanosecond switching time is achieved by adopting a differential current-steering technique. The total measured rise and fall time are 75 ps envisaging that switching rates up to 13 Gb/s are achievable. To our best knowledge, this is the fastest, lowest insertion loss V-band SPST switch yet reported that can operate over a wide bandwidth of 30 GHz.

Job strain, effort-reward imbalance, and heavy drinking: A study in 40,851 employees

Objective: The objective of this study was to examine the relationship of the job strain model and the effort-reward imbalance model with heavy drinking.

Voltage-activated currents in cardiac myocytes of the blue mussel, Mytilus edulis

Voltage-sensitive ionic currents were identified and characterised in ventricular myocytes of the bivalve mollusc, Mytilus edulis, using the whole-cell patch-clamp technique. Two outward currents could be distinguished. A potassium A current (I-A) activated at - 30 mV from a holding potential of - 60 mV. This transient current was inactivated by holding the cells at a potential of - 40 mV and was also blocked by applying 4-aminopyridine (3 mM) to the external bath solution. A second current was identified as a delayed rectifier (I-K). This also activated at - 30 mV but exhibited a sustained time course and was still activated at a holding potential of - 40 mV. Both outward currents were reduced in the presence of tetraethylammonium ions (30 mM). A small number of heart cells also showed an inward sodium current (I-Na). This current appeared at potentials more positive than - 50 mV, reached a maximum at - 20 mV, and decreased with further depolarisation. I-Na was inactivated at a holding potential of - 40 mV and was blocked by tetrodotoxin (1 mu M). A second inward current had a sustained time course and was not inactivated by holding the cell at a potential of -40 mV, and was also not abolished by tetrodotoxin. This current peaked at 0 mV, decreasing with further depolarisation. Furthermore, it was enhanced by the addition of barium ions (3 mM) to the bath and was blocked by external cobalt (2 mM) or nifedipine (15 mu M) These findings are consistent with this being an L-type calcium current (I-Ca) The possible physiological roles of these currents in M. edulis heart are discussed. (C) 1999 Elsevier Science Inc. All rights reserved.

Population pharmacokinetic model of canrenone after intravenous administration of potassium canrenoate to paediatric patients

Objectives: To characterize the population pharmacokinetics of canrenone following administration of potassium canrenoate in paediatric patients. Patients and Methods: Data were collected prospectively from 23 paediatric patients (2 days to 10 years of age; median weight 4 kg, range 2.16-28.0 kg) who received intravenous potassium canrenoate (K-canrenoate) as part of their intensive care therapy for removal of retained fluids e.g. in pulmonary oedema due to chronic lung disease and for the management of congestive heart failure. Plasma samples were analysed by HPLC for determination of canrenone (the major metabolite and pharmacologically active moiety) and the data subjected to pharmacokinetic analysis using NONMEM. Results: A one-compartment model best described the data. The only significant covariate was weight (WT). The final population models for canrenone clearance (CL/F) and volume of distribution (V/F) were CL/F (L/hr) = 11.4 × (WT /70.0)(0.75) and V/F (L) = 374.2 × (WT/70) where WT is in kg. The values of CL/F and V/F in a 4 kg child would be 1.33 L/hr and 21.4 L, respectively, resulting in an elimination half-life of 11.2 hr. Conclusions: The range of estimated CL/F in the study population was 0.67-7.38 L/hr. The data suggest that adjustment of K-canrenoate dosage according to body weight is appropriate in paediatric patients