Generation of squeezed light vacuum enabled by coherent population trapping.

We demonstrate the possibility to generate squeezed vacuum states of light by four wave mixing (FWM) enabled coherent population trapping in a metastable helium cell at room temperature. Contrary to usual FWM far detuned schemes, we work at resonance with an atomic transition. We investigate the properties of such states and show that the noise variances of the squeezed and anti-squeezed quadratures cannot be explained by the simple presence of losses. A specific model allows us to demonstrate the role played by spontaneous emitted photons, which experience squeezing while propagation inside of the cell. This theoretical model, which takes into account both residual absorption and spontaneous emission, leads to an excellent agreement with the experimental data without any adjusted parameter.

Ultrafast Double Pulse All-Optical Reswitching of a Ferrimagnet.

All-optical reswitching has been investigated in the half-metallic Heusler ferrimagnet Mn_{2}Ru_{0.9}Ga, where Mn atoms occupy two inequivalent sites in the XA-type structure. The effect of a second 200 fs, 800 nm laser pulse that follows the first pump pulse, when both are above the threshold for switching, is studied as a function of t_{12}, the time between them. Aims were to determine the minimum time needed for reswitching and to identify the physical mechanisms involved. The time trajectory of the switching process on a plot of sublattice angular momentum, S^{4a} vs S^{4c}, is in three stages; when t<0.1 ps, the sublattice moments are rapidly disordered, but not destroyed, while conserving net angular momentum via optical spin-wave excitations. This leads to transient parallel alignment of the residual Mn spins in the first quadrant. The net angular momentum associated with the majority sublattice then flips after about 2 ps, and a fully reversed ferrimagnetic state is then established via the spin-lattice interaction, which allows reswitching provided t_{12}>10 ps.

Transverse drag of slow light in moving atomic vapor.

The Fresnel-Fizeau effect of transverse drag, in which the trajectory of a light beam changes due to the transverse motion of the optical medium, is usually extremely small and hard to detect. We observe transverse drag in a moving hot-vapor cell, utilizing slow light due to electromagnetically induced transparency (EIT). The drag effect is enhanced by a factor 3.6×105, corresponding to the ratio between the light speed in vacuum and the group velocity under EIT conditions. We study the contribution of the thermal atomic motion, which is much faster than the mean medium velocity, and identify the regime where its effect on the transverse drag is negligible.

Phase-sensitive amplification via coherent population oscillations in metastable helium at room temperature.

In this Letter, we report our experimental results on phase-sensitive amplification (PSA) in a nondegenerate signal-idler configuration using ultranarrow coherent population oscillations in metastable helium at room temperature. We achieved a high PSA gain of nearly 7 with a bandwidth of 200 kHz by using the system at resonance in a single-pass scheme. Further, the measured minimum gain is close to the ideal value, showing that we have a nearly pure PSA. This is also confirmed from our phase-to-phase transfer curves measurements, illustrating that we have a nearly perfect squeezer, which is interesting for a variety of applications.

Eclampsia-scenario in a hospital--a ten years study.

This cross sectional record based institutional study was conducted in the Department of Obstetrics & Gynaecology, Burdwan Medical College, Burdwan over ten years (1999-2008) aiming analysis of eclamptic mothers for evaluation of maternal and perinatal outcome with different anticonvulsant medications. Total 5991 pregnant mothers with eclampsia admitted in the inpatient department of the tertiary care teaching hospital were recruited for the study, irrespective of their previous antenatal check up history. Subjects with known seizure disorders were excluded from the study. The subjects were managed according to standard regimens (Menon, Ph-sodium, diazepam & magnesium sulphate) and results were documented in standardised format. Case fatality rate, mean induction delivery time & birth-weight, perinatal mortality rates were recorded. Study reveals that the incidence of eclampsia <20 years was 6.97% and majority (5.41%) came from rural areas. Eclampsia was noted primarily in primigravida (7.43%) and unbooked (6.41%) mothers. Ante partum eclampsia predominated (64%) and incidence of caesarean section was 22.25%.The overall case fatality rate was 6.05% and eclampsia contributed 27.85% of all maternal deaths during the last two years of the study period. The overall incidence of low birth weight baby was 26.96% and perinatal mortality was 30.33% (1411/4651).The incidence of perinatal mortality and low birth weight babies are lower in the last 4 years when compared to earlier studies. Proper socio-demographic assessment of pregnancy with eclampsia, planned delivery, shorter induction delivery interval, good control of convulsion by magnesium sulphate, intensive intranatal monitoring causes less maternal and perinatal morbidity and mortality.

Single pulse all-optical toggle switching of magnetization without gadolinium in the ferrimagnet Mn2RuxGa.

Energy-efficient control of magnetization without the help of a magnetic field is a key goal of spintronics. Purely heat-induced single-pulse all-optical toggle switching has been demonstrated, but so far only in Gd-based amorphous ferrimagnet films. In this work, we demonstrate toggle switching in films of the half-metallic ferrimagnetic Heusler alloys Mn2RuxGa, which have two crystallographically-inequivalent Mn sublattices. Moreover, we observe the switching at room temperature in samples that are immune to external magnetic fields in excess of 1 T, provided they exhibit a compensation point above room temperature. Observation of the effect in compensated ferrimagnets without Gd challenges our understanding of all-optical switching. The dynamic behavior indicates that Mn2RuxGa switches in 2 ps or less. Our findings widen the basis for fast optical switching of magnetization and break new ground for engineered materials that can be used for nonvolatile ultrafast switches using ultrashort pulses of light.

Purification and properties of retinol- and retinoic acid-binding proteins from a transplantable mouse colon tumor.

Cellular retinol-binding protein and retinoic acid-binding protein, the possible mediators of the action of retinoids in epithelial differentiation and control of tumorigenesis, have been reproducibly purified from mouse colon tumor 26, and some of their properties were studied. The main steps of purification involved acid-precipitation, DEAE-Sephadex, CM-cellulose and Sephadex G-100 chromatography. About 2 mg of the binding proteins were isolated from 60 g tumor. The purified preparations showed only two protein bands on polyacrylamide gel electrophoresis. The two binding proteins were partially resolved by sedimentation equilibrium technique; but was completely separable by preparative electrophoresis in the presence of sodium dodecyl sulfate. The retinol- and retinoic acid-binding proteins are presumably monomers with molecular weights of 15,500 and 14,600, respectively, as determined by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. On gel filtration however, both the binding proteins retarded to the same molecular size of 17,800. On preparative columns, both the proteins expressed the same isoelectric pH, 4.5. Both proteins of the tumor possessed functional thiol groups. The mercurial inhibition of the binding capacity of the proteins for their ligands was reversible upon treatment with thiol compounds.

Contributions of distal and proximal promoter elements to glucocorticoid regulation of osteocalcin gene transcription.

Previous studies identified several glucocorticoid response elements (GREs) in the 5'-promoter region of the rat osteocalcin (OC) gene by purified receptor binding. The present study addresses functionality of the GRE sequences in the proximal promoter at nucleotide (nt) -16 to -1 downstream of the TATA element together with the GRE half-element in the OC box at nt -86 to -81. This was done by assaying glucocorticoid responsiveness [at 10(-6) M dexamethasone (DEX)], and in combination with 10(-8) M 1,25-dihydroxyvitamin D3, of a series of deleted and mutated OC promoter reporter constructs (OCCAT) in osteoblast-like cells, the ROS 17/2.8 rat osteosarcoma line. Promoter deletion analysis revealed an additional GRE in the distal promoter at nt -697 to -683 that functions to suppress OC transcription. In the absence of this upstream negative GRE (nGRE), the -531 OCCAT construct exhibited enhanced promoter activity in response to DEX (1.8-fold DEX/Control), but further deletion (-348 and -108 OCCAT constructs) restored DEX suppression to OC promoter activity (0.6- and 0.8-fold DEX/Control, respectively). Mutations introduced in both the proximal GRE (nt -16 to -1) and the half-GRE in the OC box, or in the proximal GRE alone, nearly abrogated DEX responsiveness of OC promoter activity. Both distal and proximal GREs specifically bound glucocorticoid receptor present in ROS 17/2.8 nuclear extracts as shown by competition with wild type and mutated oligonucleotides and antibody inhibition of binding. Furthermore, both GREs, independently, conferred DEX-responsive transcriptional repression to the heterologous thymidine kinase basal promoter. We also report that glucocorticoid suppression of 1,25-dihydroxyvitamin D3-stimulated transcription occurs independently of distal or proximal GREs. Taken together, these results demonstrate that in vivo responsiveness of OC to DEX involves the integrative activities of several functional promoter elements.

Bacillus infections in patients with cancer.

Eighteen febrile patients experienced 24 episodes of Bacillus bacteremias from January 1978 to June 1986. Bacillus species isolated included Bacillus cereus (eight cases), Bacillus circulans (three), Bacillus subtilis (two), Bacillus pumilus (two), Bacillus licheniformis (one), Bacillus sphaericus (one), Bacillus coagulans (one), and six that could not be speciated. Fifteen patients had lymphoma or leukemia and three had breast cancer. Nine patients were neutropenic (polymorphonuclear neutrophil count, less than 1.0 x 10(9)/L), seven patients had a Hickman catheter in place, and 14 had recently received chemotherapy. Twelve of the bacteremic episodes were clinically significant, and four of these 12 involved Hickman catheters. Catheter removal was ultimately necessary in all four patients. Scanning and transmission electron microscopy was performed on one of the removed Hickman catheters and showed Bacillus organisms embedded in a biofilm composed of gram-positive cocci and glycocalyx. Bacillus species were uniformly susceptible to vancomycin, imipenem, and aminoglycosides, with penicillin susceptibilities being variable. Bacillus appears to be another gram-positive organism now being recognized as a bacterial pathogen for compromised hosts. When such infections involve long-term indwelling venous access devices, treatment should include immediate catheter removal as well as antibiotic therapy.

Basal and vitamin D-responsive activity of the rat osteocalcin promoter in stably transfected osteosarcoma cells: requirement of upstream sequences for control by the proximal regulatory domain.

Osteocalcin (OC) is a bone-specific vitamin D- responsive protein that is developmentally expressed during osteoblast differentiation. In transient transfection assays, as little as approximately 0.1 kilobase (kb) of the OC proximal promoter is sufficient for basal expression. Because eukaryotic genes are packaged as nucleosomes that contribute to both chromatin organization and transcriptional control, we functionally examined the activity of OC promoter constructs within a chromatin context. ROS 17/2.8 osteosarcoma cells were stably transfected with a series of rat OC promoter-reporter constructs, containing progressive 5'-deletions. The results demonstrate that in contrast to transient transfection assays, the proximal 0.11-kb promoter is no longer active when integrated in the genome. Progressive gain of basal expression with 0.35-, 0.53-, and 0.72-kb promoters suggests that upstream sequences facilitate the formation of an appropriate higher order nuclear structure, thereby potentiating the activity of the chromosomally integrated proximal promoter elements. This is consistent with location of both deoxyribonuclease I (DNase I)-hypersensitive sites and nuclear matrix protein-DNA interaction sites in the osteocalcin promoter. Vitamin D responsiveness in the stably transfected cells is obtained with the inclusion of 0.53 kb or additional upstream promoter sequences. Therefore, these sequences satisfy the requirements for binding of basal and enhancer transcription factors as well as interactions between them within a chromatin context. Both maximal basal expression and maximal vitamin D responsiveness are obtained with cells carrying either the 0.72-kb or the 1.1-kb promoter fragment. Cells carrying the 1.1-kb promoter show DNase I hypersensitivity at both the basal promoter and the vitamin D response element-containing domains, locations that also exhibit DNase I hypersensitivity in the endogenous OC promoter. In addition, we have documented changes in the basal activity and vitamin D responsiveness of the stably integrated 1.1 kb promoter as a function of cell density-mediated growth inhibition, which is accompanied by up-regulation of bone phenotypic genes. Thus, important aspects of OC gene transcriptional regulation that cannot be investigated in transient transfection assays can be addressed using ROS 17/2.8 cells stably transfected with OC promoter-reporter constructs.

Developmental expression and activities of specific fos and jun proteins are functionally related to osteoblast maturation: role of Fra-2 and Jun D during differentiation.

Developmental studies of oncogene expression implicate the Fos and Jun family of transcription factors in the regulation of bone growth and differentiation. Promoters of many developmentally regulated genes, including osteocalcin, a marker of osteoblast differentiation, contain AP-1 sites that bind Fos/Jun dimers. Here, we demonstrate that the selective expression of fos- and jun-related genes is functionally related to the stage of osteoblast growth and differentiation in vitro. During osteoblast proliferation, nuclear protein levels of all seven activating protein-1 (AP-1) members are maximal. Subsequently, during the period of extracellular matrix maturation, levels decline. In fully differentiated osteoblasts, Fra-2 and (to a lesser extent) Jun D are the principal AP-1 members detectable by Western blot analysis. AP-1 complex composition and binding activity also exhibit developmental changes. All Fos and Jun family members are involved in AP-1 complex formation in proliferating cells, whereas Fra-2 and Jun D predominate in AP-1 complexes in differentiated osteoblasts. Overexpression of Fos and Jun family members in ROS 17/2.8 cells markedly affects the expression of an osteocalcin promoter-chloramphenicol acetyltransferase construct. Coexpression of only one AP-1 pair, Fra-2 and Jun D, stimulated reporter expression, whereas coexpression of other AP-1 pairs down-regulated expression (i.e. c-jun and any Fos family member) or had no effect (i.e. Fra-1 and Jun B). Promoter deletion analyses indicate that these effects are site specific. Consequential effects of Fra-2 on osteoblast differentiation are further demonstrated by antisense studies in which osteoblast differentiation and the development of a bone tissue-like organization were suppressed. Consistent with recent findings suggesting that AP-1 complex composition can selectively regulate gene transcription, our findings demonstrate that differential expression of Fos and Jun family members could play a role in the developmental regulation of bone-specific gene expression and, as a result, may be functionally significant for osteoblast differentiation.

Transforming growth factor-beta 1 responsiveness of the rat osteocalcin gene is mediated by an activator protein-1 binding site.

Osteocalcin (OC), a bone specific protein expressed during differentiation and mineralization of the bone extracellular matrix, is down-regulated upon treatment with transforming growth factor (TGF)-beta 1. To address the potential role of OC gene expression in relation to TGF-beta 1 regulation of bone formation and resorption, we examined the transcriptional activity of the rat OC promoter after TGF-beta 1 treatment. 5' deletion analysis of rat OC promoter-chloramphenicol acetyltransferase constructs demonstrated that TGF-beta 1 treatment repressed chloramphenicol acetyltransferase activity by 2.4-fold in transient transfections of ROS 17/2.8 cells. A 29-bp region between -162 and -134 identified as the TGF-beta 1 response domain, conferred TGF-beta 1 responsiveness to the -108 to +24 rat OC basal promoter in an orientation dependent manner. Mutation of an activator protein-1/cAMP-response element-like motif (- 146 to -139) abolished TGF-beta 1 responsiveness of the construct. In vitro gel-mobility shift and competition assays using wild-type and mutated oligonucleotides and antibodies indicate that Fra-2, a Fos related transcription factor, binds to this motif. We show that Fra-2 is an activator of the OC promoter, and TGF-beta 1 inhibits this activation. Our results demonstrate that Fra-2 is hyperphosphorylated upon TGF-beta 1 treatment of ROS 17/2.8 cells. Additionally, treatment of cells with a staurosporine protein kinase C inhibitor abrogates TGF-beta 1 mediated down-regulation of the OC promoter activity. Together, these results demonstrate that TGF-beta 1 responsiveness of the rat osteocalcin gene in ROS 17/2.8 cells is mediated through an activator protein-1 like cis-acting element that interacts with Fra-2. Furthermore, our results are consistent with a critical role for TGF-beta 1 induced phosphorylation of Fra-2 in the repression of OC gene transcription.

Differential regulation of the two principal Runx2/Cbfa1 n-terminal isoforms in response to bone morphogenetic protein-2 during development of the osteoblast phenotype.

Cbfa1/Runx2 is a transcription factor essential for bone formation and osteoblast differentiation. Two major N-terminal isoforms of Cbfa1, designated type I/p56 (PEBP2aA1, starting with the sequence MRIPV) and type II/p57 (til-1, starting with the sequence MASNS), each regulated by distinct promoters, are known. Here, we show that the type I transcript is constitutively expressed in nonosseous mesenchymal tissues and in osteoblast progenitor cells. Cbfa1 type I isoform expression does not change with the differentiation status of the cells. In contrast, the type II transcript is increased during differentiation of primary osteoblasts and is induced in osteoprogenitors and in premyoblast C2C12 cells in response to bone morphogenetic protein-2. The functional equivalence of the two isoforms in activation and repression of bone-specific genes indicates overlapping functional roles. The presence of the ubiquitous type I isoform in nonosseous cells and before bone morphogenetic protein-2 induced expression of the type II isoform suggests a regulatory role for Cbfa1 type I in early stages of mesenchymal cell development, whereas type II is necessary for osteogenesis and maintenance of the osteoblast phenotype. Our data indicate that Cbfa1 function is regulated by transcription, cellular protein levels, and DNA binding activity during osteoblast differentiation. Taken together, our studies suggest that developmental timing and cell type- specific expression of type I and type II Cbfa isoforms, and not necessarily molecular properties or sequences that reside in the N-terminus of Cbfa1, are the principal determinants of the osteogenic activity of Cbfa1.

Parathyroid-responsive modifications in the nuclear matrix of ROS 17/2.8 rat osteosarcoma cells.

PTH is a mediator of skeletal development and remodeling that influences gene expression in osteoblastic cells. It is well established that PTH modulates the activity of membrane-associated second messenger signal transduction pathways. In these studies we have addressed the potential contribution of components of cell structure to the integration of PTH-related regulatory signals that influence the expression of bone cell genes. Chronic treatment of ROS 17/2.8 rat osteosarcoma cells with PTH is accompanied by changes in gene expression that are at least in part transcriptionally controlled. To explore the involvement of nuclear architecture in PTH-responsive modifications in gene expression, we investigated changes in the nuclear matrix after PTH treatment. Consistent with a role for the nuclear matrix in determining spatial organization and topology of chromatin as well as in the localization and targeting of transcription factors, we observed PTH-associated changes in a 200-kilodalton nuclear matrix protein in response to PTH. A significant down-regulation of synthesis was observed when nuclear matrix proteins were resolved electrophoretically in two-dimensional gels. This protein was restricted to the nuclear matrix and was not detected in the chromatin or cytoskeletal cellular fractions. These alterations in nuclear matrix proteins that occur after PTH treatment in osteosarcoma cells were phenotype related. They did not occur in UMR-106 POL or H4 hepatoma cells. Our findings support a role for the nuclear matrix in transducing PTH-mediated regulatory signals to facilitate the extent to which genes in osteoblasts are transcribed.

Classical Alzheimer features and cholinergic dysfunction: towards a unifying hypothesis?

OBJECTIVE: Our autopsy studies show possible links between classical Alzheimer pathology and decreased expression of nicotinic acetylcholine receptors. For further elucidation we are now using in vitro models. We report preliminary evidence for the impact of beta-amyloid on nicotinic receptor expression in hippocampal dissociation culture. METHODS: Cultures (E18 rats) were grown in a serum-free medium and incubated at 8 days in vitro for 3 days with 1 microM Abeta1-42. Expression of alpha4, alpha7, and beta2 nicotinic receptor subunit protein was assessed immunohistochemically and rated semiquantitatively. RESULTS: Abeta1-42 incubation resulted in a massive reduction of alpha4 protein-expressing neurons, this effect was less pronounced for the alpha7 and beta2 subunit protein. CONCLUSION: These findings provide first evidence for a direct impact of classical Alzheimer pathology features on nicotinic receptor expression in vitro. Our model will be useful for testing the potential of drugs to stop or reverse these effects.

Isolation and characterization of a cyclic nucleotide-independent protein kinase from Leishmania donovani.

We describe here a protein kinase from the promastigote form of the parasitic protozoan, Leishmania donovani, purified to near homogeneity to a single-subunit, 34-kDa protein. This enzyme does not require a cofactor, and has several characteristics in common with the catalytic subunit of mammalian cAMP-dependent protein kinase, for example, preference for kemptide as a substrate, phosphorylation of serine residues of protamine and inhibition by the mammalian heat-stable inhibitor. The leishmanial enzyme can associate with the regulatory subunit of mammalian cAMP-dependent protein kinase to form an inactive holoenzyme that is activated by cAMP and is protected from inhibition by thiol reagents. From these results it is concluded that L. donovani promastigotes possess a protein kinase which has similar characteristics with the mammalian catalytic subunit of cAMP-dependent protein kinase.

Autopsy findings and clinical diagnoses: a review of 1,000 cases.

The protocols of 1,000 consecutive adult patients autopsied during the period June 1983 to December 1988 were retrospectively analyzed and the findings were compared with clinical diagnoses. The autopsy rates during this period ranged between 23% and 27% of hospital deaths. Eighty-seven percent of the autopsied patients were between 15 and 59 years of age. Major discrepancies between the autopsy reports and the clinical diagnoses were present in 31.7% of all autopsy reports reviewed. Infectious diseases were the most common cause of death (46.8%), followed by cardiovascular diseases (17.1%) and neoplastic diseases (14.3%). Infections were clinically recognized in 66.7% of cases and were missed or found to be incorrect in 33.3% of cases. Tuberculosis comprised 33.8% of the major bacterial infections and was clinically diagnosed in 82% of cases. Eighty-nine percent of the major fungal infections were not suspected clinically. Rheumatic heart disease (43.8%) was the most common cardiovascular disorder and was clinically diagnosed in 93.3% of cases. Pulmonary vascular episodes were the least common cause of death and were not suspected clinically in 62.9% of cases. Malignancies were incorrectly diagnosed in 25.8% of cases. We conclude from this study that routine autopsies revealed major unexpected findings that are of clinical importance, and that a continued emphasis on autopsy evaluation is necessary for the improvement of the quality of patient care.

Nuclear morphometric analysis of non-Hodgkin's lymphoma.

Nuclear morphometric data on resin-embedded sections have been utilized to classify 50 cases of non Hodgkin's lymphoma (NHL) and to compare with morphological classification. Nuclear morphometric parameters studied were maximum diameter (Dmax), area, perimeter, form factor (FF) and nuclear contour index (NCI). The first three are determinants of the size, and the latter two indicate the shape of nuclei. Based on Dmax, small (4.5-5.5 microns), intermediate (5.5-7.0 microns) and large (7.0-12.0 microns) cell lymphomas were identified, which correlate with the low, intermediate and high grade lymphomas respectively of the Working Formulation. Determination of form factor further helped to subclassify these cases into lymphomas of B cell other than of follicular centre cell origin (FF = 0.7-1.0), follicular centre cell lymphomas (FF = 0.55-0.75) and T-cell lymphomas (FF less than 0.55). Pleomorphism factor is an objective assessment of the degree of morphological pleomorphism and is generally proportional to the grade of malignancy.

The cAMP-binding proteins of Leishmania are not the regulatory subunits of cAMP-dependent protein kinase.

The most commonly used method to determine the cAMP binding activity in cytosolic extracts of promastigotes of Leishmania spp. underestimated by approximately 11.5-fold the total amount of [(3)H]cAMP bound, when compared with results obtained by the modified Millipore filter technique. Three cAMP-binding proteins (BPI, BPII and BPIII) were partially purified and characterized. The native molecular masses of BPI, BPII and BPIII were estimated to be 105, 155 and 145 kDa, respectively. The binding of [(3)H]cAMP to these proteins was affected to different extents by several cAMP analogues. Antibodies directed against the types I and II regulatory subunits of PKA did not cross-react with the leishmanial extract. Photoaffinity labeling of the cytosolic extracts with 8-N(3)-[(32)P]cAMP specifically labeled a band of M(r) 116000 and a band of M(r) 80000 partially saturable by cAMP. From these results, it is concluded that the leishmanial cAMP-binding proteins appear to belong to a different class distinct from the regulatory subunits of cAMP-dependent protein kinases.

Outbreak of Salmonella worthington meningitis & septicaemia in a hospital at Chandigarh (north India).

During August 1988 an outbreak of hospital acquired infection due to S. worthington has been reported at the Nehru Hospital, Postgraduate Institute of Medical Education and Research, Chandigarh. A total of seven neonates presented with the clinical features of meningitis and septicaemia during this outbreak and six babies died. S. worthington was isolated from blood and cerebrospinal fluid respectively. The same strains were isolated from the baby warmer mattress, baby cot, suction machine bottle and wall of the fridge. Samples from doctors, nurses and apparently healthy babies born during this period did not grow the above organism. This appears to be the first report on S. worthington in human beings from India. The outbreak was controlled by thorough cleaning and fumigation. The organisms were also mostly sensitive to antibiotics used, in contrast to the multiple drug resistant pattern reported from elsewhere.