RESUMEN
Presidents and executive branch agencies often have adversarial relationships. Early accounts suggest that these antagonisms may have been deeper and broader under President Trump than under any recent President. Yet careful appraisals have sometimes shown that claims about what President Trump has done to government and politics are over-stated, require greater nuance, or are just plain wrong. In this article, we use federal employment records from the Office of Personnel Management to examine rates of entry and exit at agencies across the executive branch during President Trump's term. A key challenge in this endeavor is that agencies vary in size dramatically, and this variability makes direct comparisons of rates of entry and exit across agencies problematic. Small agencies are overrepresented among agencies with large and small rates. Yet small agencies do important work and cannot simply be ignored. To address such small-area issues, we use a Bayesian hierarchical model to generate size-adjusted rates that better reflect the fundamental uncertainty about what is happening in small agencies as well as the substantial likelihood that these entities are less unusual than raw statistics imply. Our analysis of these adjusted rates leads to three key findings. First, total employment at the end of the Trump administration was largely unchanged from where it began in January of 2017. Second, this aggregate stability masks significant variation across departments, with immigration-focused bureaus and veterans-affairs bureaus growing significantly and certain civil-rights focused bureaus exhibiting signs of stress. Finally, compared to the first terms of Presidents Bush and Obama, separation rates under President Trump were markedly higher for most agencies.
Asunto(s)
Política , United States Government Agencies , Estados Unidos , Teorema de Bayes , Máscaras , ProbabilidadRESUMEN
The development of reliable multivariate calibration models for spectroscopic instruments in on-line/in-line monitoring of chemical and bio-chemical processes is generally difficult, time-consuming and costly. Therefore, it is preferable if calibration models can be used for an extended period, without the need to replace them. However, in many process applications, changes in the instrumental response (e.g. owing to a change of spectrometer) or variations in the measurement conditions (e.g. a change in temperature) can cause a multivariate calibration model to become invalid. In this contribution, a new method, systematic prediction error correction (SPEC), has been developed to maintain the predictive abilities of multivariate calibration models when e.g. the spectrometer or measurement conditions are altered. The performance of the method has been tested on two NIR data sets (one with changes in instrumental responses, the other with variations in experimental conditions) and the outcomes compared with those of some popular methods, i.e. global PLS, univariate slope and bias correction (SBC) and piecewise direct standardization (PDS). The results show that SPEC achieves satisfactory analyte predictions with significantly lower RMSEP values than global PLS and SBC for both data sets, even when only a few standardization samples are used. Furthermore, SPEC is simple to implement and requires less information than PDS, which offers advantages for applications with limited data.
Asunto(s)
Modelos Estadísticos , Espectroscopía Infrarroja Corta/métodos , Calibración , Análisis de Componente Principal , Espectroscopía Infrarroja Corta/normasRESUMEN
Previous studies have shown that neurokinin 1 receptor (NK1R) occurs naturally in human glioblastomas and its stimulation causes cell proliferation. In the present study we show that stimulation of NK1R in human U373 glioblastoma cells by substance P increases Akt phosphorylation by 2.5-fold, with an EC(50) of 57 nM. Blockade of NK1R lowers basal phosphorylation of Akt, indicating the presence of a constitutively active form of NK1R; similar results are seen in U251 MG and DBTRG-05 glioblastoma cells. Linkage of NK1R to Akt implicates NK1R in apoptosis of glioblastoma cells. Indeed, treatment of serum-starved U373 cells with substance P reduces apoptosis by 53 +/- 1% (p < 0.05), and treatment with NK1R antagonist L-733,060 increases apoptosis by 64 +/- 16% (p < 0.01). Further, the blockade of NK1R in human glioblastoma cells with L-733,060 causes cleavage of Caspase-3 and proteolysis of poly (ADP-ribose) polymerase. Experiments designed to elucidate the mechanism of NK1R-mediated Akt phosphorylation revealed total involvement of non-receptor tyrosine kinase Src and phosphatidyl-3-kinase, a partial involvement of epidermal growth factor receptor, and no involvement of mitogen-activated protein/extracellular signal-related kinase. Taken together, the results of the present study indicate a key role for NK1R in glioblastoma apoptosis.
Asunto(s)
Apoptosis/fisiología , Neoplasias Encefálicas/patología , Glioblastoma/patología , Receptores de Neuroquinina-1/metabolismo , Receptores de Neuroquinina-1/fisiología , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Medios de Cultivo Condicionados/análisis , Relación Dosis-Respuesta a Droga , Humanos , Inmunohistoquímica , Antagonistas del Receptor de Neuroquinina-1 , Proteína Oncogénica v-akt/metabolismo , Fosforilación , Proteínas Proto-Oncogénicas c-akt/metabolismo , Sustancia P/análisis , Sustancia P/farmacologíaRESUMEN
Non-invasive NIR spectrometry has been used to monitor in situ the seed stage of a streptomyces fermentation process. The main spectral change occurred at 7263 cm(-1) in the 1st derivative spectrum, and from comparison with off-line NIR spectra acquired of components present in the fermentation broth, can be attributed to biomass. The biomass signal was constant for the first 20 h of the seed stage, after which it decreased before increasing again. The time at which the minimum occurred in the NIR profile was either the same or slightly earlier than that at which a maximum in the carbon dioxide evolution rate (CER) occurred. The changes observed for the biomass signal in the NIR spectra can be attributed to growth and then fragmentation of mycelia, which indicates a change in metabolic activity. Hence, it may be possible to use NIR spectrometry in situ to determine the optimum transfer time for the seed stage of a fermentation process. Spectra were also acquired of the final stage of the same fermentation process. The variation in the biomass signal in the NIR spectra was more complicated in the final stage owing to changes in stir rate, and biomass concentration and morphology.
Asunto(s)
Reactores Biológicos , Microbiología Industrial , Streptomyces/fisiología , Biomasa , Fermentación , Espectroscopía Infrarroja Corta , Factores de Tiempo , ViscosidadRESUMEN
In an ongoing investigation of the effects of age on G protein-coupled receptor signaling in human atrial tissue, we have found that the density of atrial muscarinic acetylcholine receptor (mAChR) increases with age but reaches statistical significance only in patients with diabetes. Moreover, we find that in elderly subjects of similar ages, those with diabetes have 1.7-fold higher levels of Galpha(i2) and twofold higher levels of Gbeta(1). Diabetes does not affect other atrial G proteins, including Galpha(i3,) Galpha(s), Galpha(o), and Gbeta(2). These data represent the first demonstration of an increase in a G(i)-coupled receptor, Galpha(i2), and Gbeta(1), in atrium of patients with diabetes. These findings suggest a molecular explanation for the increased risk of cardiac disease in patients with diabetes, because increased signaling through G(i) has been shown to lead to the development of dilated cardiomyopathy.
Asunto(s)
Envejecimiento/fisiología , Diabetes Mellitus/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/metabolismo , Subunidades beta de la Proteína de Unión al GTP/metabolismo , Miocardio/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Receptores Muscarínicos/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Subunidad alfa de la Proteína de Unión al GTP Gi2 , Atrios Cardíacos/metabolismo , Humanos , Masculino , Persona de Mediana Edad , TritioRESUMEN
Substance P receptor (SPR), a G protein-coupled receptor (GPCR), is found in human glioblastomas, and has been implicated in their growth. Consistent with a role for SPR in cell growth, activation of SPR in U373 MG human glioblastoma cells leads to the phosphorylation of mitogen-activated protein kinases [extracellular signal-regulated kinase 1 and 2 (ERK1/2)] and stimulation of cell proliferation. The purpose of the present study was to elucidate the pathway through which these actions occur. Using either the epidermal growth factor receptor (EGFR) kinase inhibitor, AG 1478, or a small-interfering RNA (siRNA) directed against human EGFR, we found that transactivation of EGFR by SPR is only marginally involved in SP-dependent ERK1/2 phosphorylation. Src, however, is shown to be a major component of SPR signaling because the Src kinase inhibitor, PP2, and a kinase-dead Src mutant both inhibit SP-dependent ERK1/2 phosphorylation. We also report that SPR stimulates the phosphorylation of protein kinase Cdelta(PKCdelta), and that this stimulation is blocked by PP2. SP-dependent ERK1/2 phosphorylation is also blocked by rottlerin, a PKCdelta inhibitor, and the calcium scavenger, BAPTA/AM. Finally, rottlerin and PP2 were both found to inhibit the growth of several glioblastoma cell lines, underscoring the potential of these agents to block glioblastoma growth.
Asunto(s)
Glioblastoma/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteína Quinasa C-delta/metabolismo , Receptores de Neuroquinina-1/metabolismo , Transducción de Señal , Acetofenonas/farmacología , Benzopiranos/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Quelantes/farmacología , Ácido Egtácico/análogos & derivados , Ácido Egtácico/farmacología , Inhibidores Enzimáticos/farmacología , Receptores ErbB/genética , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Glioblastoma/tratamiento farmacológico , Glioblastoma/patología , Humanos , Oligonucleótidos Antisentido/farmacología , Fosforilación/efectos de los fármacos , Proteína Quinasa C-delta/antagonistas & inhibidores , Pirimidinas/farmacología , Quinazolinas , ARN Interferente Pequeño/farmacología , Tirfostinos/farmacologíaRESUMEN
G protein-coupled receptor kinases (GRKs) phosphorylate agonist-occupied G protein-coupled receptors, leading to receptor desensitization. Seven GRKs, designated GRK1 through 7, have been characterized. GRK5 is negatively regulated by protein kinase C. We investigated whether human substance P receptor (hSPR) is a substrate of GRK5. We report that membrane-bound hSPR is phosphorylated by purified GRK5, and that both the rate and extent of phosphorylation increase dramatically in the presence of substance P. The phosphorylation has a high stoichiometry (20+/-4 mol phosphate/mol hSPR) and a low K(m) (1.7+/-0.1 nM). These data provide the first evidence that hSPR is a substrate of GRK5.
Asunto(s)
Proteínas de Unión al GTP/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Receptores de Neuroquinina-1/metabolismo , Sustancia P/metabolismo , Secuencia de Aminoácidos , Animales , Catálisis , Línea Celular , Membrana Celular/metabolismo , Quinasa 5 del Receptor Acoplado a Proteína-G , Humanos , Cinética , Datos de Secuencia Molecular , Fosforilación , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/aislamiento & purificación , Receptores de Neuroquinina-1/agonistas , Spodoptera , Especificidad por SustratoRESUMEN
Cardiac G protein-coupled receptors that function through stimulatory G protein Galpha(s), such as beta(1)- and beta(2)-adrenergic receptors (beta(1)ARs and beta(2)ARs), play a key role in cardiac contractility. Recent data indicate that several Galpha(s)-coupled receptors in heart also activate Galpha(i), including beta(2)ARs (but not beta(1)ARs). Coupling of cardiac beta(2)ARs to Galpha(i) inhibits adenylyl cyclase and opposes beta(1)AR-mediated apoptosis. Dual coupling of beta(2)AR to both Galpha(s) and Galpha(i) is likely to alter beta(2)AR function in disease, such as congestive heart failure in which Galpha(i) levels are increased. Indeed, heart failure is characterized by reduced responsiveness of betaARs. Cardiac betaAR-responsiveness is also decreased with aging. However, whether age increases cardiac Galpha(i) has been controversial, with some studies reporting an increase and others reporting no change. The present study examines Galpha(i) in left ventricular membranes from young and old Fisher 344 rats by employing a comprehensive battery of biochemical assays. Immunoblotting reveals significant increases with age in left ventricular Galpha(i2), but no changes in Galpha(i3), Galpha(o), Galpha(s), Gbeta(1), or Gbeta(2). Aging also increases ADP-ribosylation of pertussis toxin-sensitive G proteins. Consistent with these results, basal as well as receptor-mediated incorporation of photoaffinity label [(32)P]azidoanilido-GTP indicates higher amounts of Galpha(i2) in older left ventricular membranes. Moreover, both basal and receptor-mediated adenylyl cyclase activities are lower in left ventricular membranes from older rats, and disabling of Galpha(i) with pertussis toxin increases both basal and receptor-stimulated adenylyl cyclase activity. Finally, age produces small but significant increases in muscarinic potency for the inhibition of both beta(1)AR- and beta(2)AR-stimulated adenylyl cyclase activity. The present study establishes that Galpha(i2) increases with age and provides data indicating that this increase dampens adenylyl cyclase activity.
Asunto(s)
Envejecimiento/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/biosíntesis , Miocardio/metabolismo , Proteínas Proto-Oncogénicas/biosíntesis , Receptores Adrenérgicos beta 1/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , Toxina de Adenilato Ciclasa , Adenilil Ciclasas/metabolismo , Animales , Subunidad alfa de la Proteína de Unión al GTP Gi2 , Toxina del Pertussis , Ratas , Ratas Endogámicas F344 , Factores de Virulencia de Bordetella/farmacologíaRESUMEN
Substance P receptor (SPR) and its naturally occurring splice-variant, lacking the C-terminal tail, are found in brain and spinal cord. Whether C-terminally truncated SPR desensitizes like full-length SPR is controversial. We used a multivaried approach to determine whether human SPR (hSPR) and a C-terminally truncated mutant, hSPRDelta325, differ in their desensitization and internalization. In HEK-293 cells expressing either hSPRDelta325 or hSPR, SP-induced desensitization of the two receptors was similar when measured by inositol triphosphate accumulation or by transient translocation of coexpressed PKCbetaII-GFP to the plasma membrane. Moreover, translocation of beta-arrestin 1 or 2-GFP (betaarr1-GFP or betaarr2-GFP) to the plasma membrane, and receptor internalization were also similar. However, hSPR and hSPRDelta325 differ in their phosphorylation and in their ability to form beta-arrestin-containing endocytic vesicles. Unlike hSPR, hSPRDelta325 is not phosphorylated to a detectable level in intact HEK293 cells, and whereas hSPR forms vesicles containing either betaarr1-GFP or betaarr2-GFP, hSPRDelta325 does not form any vesicles with betaarr1-GFP, and forms fewer vesicles with betaarr2-GFP. We conclude that truncated hSPR undergoes agonist-dependent desensitization and internalization without detectable receptor phosphorylation.