Informing ocean color inversion products by seeding with ancillary observations.

Ocean reflectance inversion algorithms provide many products used in ecological and biogeochemical models. While a number of different inversion approaches exist, they all use only spectral remote-sensing reflectances (Rrs(λ)) as input to derive inherent optical properties (IOPs) in optically deep oceanic waters. However, information content in Rrs(λ) is limited, so spectral inversion algorithms may benefit from additional inputs. Here, we test the simplest possible case of ingesting optical data ('seeding') within an inversion scheme (the Generalized Inherent Optical Property algorithm framework default configuration (GIOP-DC)) with both simulated and satellite datasets of an independently known or estimated IOP, the particulate backscattering coefficient at 532 nm (bbp(532)). We find that the seeded-inversion absorption products are substantially different and more accurate than those generated by the standard implementation. On global scales, seasonal patterns in seeded-inversion absorption products vary by more than 50% compared to absorption from the GIOP-DC. This study proposes one framework in which to consider the next generation of ocean color inversion schemes by highlighting the possibility of adding information collected with an independent sensor.

Qualitative estimates of soil disturbance in the vicinity of CANDU stations, utilizing measurements of 137Cs and 210Pb in soil cores.

Anthropogenically derived 14C has been used to trace recent carbon input in a study of carbon accumulation and turnover in Canadian soils. In order to do so, documentation of the undisturbed nature of the soil horizons sampled was of prime concern. Although all the sites chosen for coring were currently uncultivated, detailed information on long-term land usage was not available. To overcome this problem, 137Cs profiles were measured in all the cores used in the study. 210Pb measurements were also made in cases where total 137Cs deposition was lower than predicted. For some sample sites, the data obtained showed correlated losses of both radionuclides, indicating that land disturbance and/or erosion had indeed occurred in these areas over the past 50 years, hence invalidating the use of those cores for carbon cycling studies. In a few cases a marked lack of correlation between these two radionuclides has made it necessary to hypothesize that chemical, rather than physical, processes have been partially responsible for the observed anomalies. Since results of this nature raise doubts about the reliability of the 137Cs method for identification of land disturbance, further investigation is warranted.

Gepirone and 1-(2-pyrimidinyl)-piperazine in vitro: human cytochromes mediating transformation and cytochrome inhibitory effects.

Biotransformation of gepirone to its principal metabolite, 1-(2-pyrimidinyl)-piperazine (1-PP), was studied in human liver microsomes and in microsomes from cDNA-transfected human lymphoblastoid cells. Formation of 1-PP from gepirone in liver microsomes proceeded with a mean apparent Km ranging from 335 to 677 microM. Coincubation with 1 microM ketoconazole reduced reaction velocity to less than 5% of control values at a gepirone concentration of 250 microM. Three other metabolites, presumed to be hydroxylated products, were also formed from gepirone. Formation of all three products was reduced to approximately 20% of control values by 1 microM ketoconazole; quinidine at 1 microM produced a small reduction in formation (91-94% of control) of two of the metabolites. 1-PP was formed from gepirone exclusively by pure P450-3A4 with a Km of 849 microM; Km values for the other metabolites were 245, 240, and 415 microM. Two of the products were also formed by P450-2D6. The results indicate that 3A4 is the principal cytochrome mediating 1-PP formation, as well as formation of the other metabolites. The properties of gepirone and 1-PP themselves as cytochrome inhibitors were tested in human liver microsomes using index reactions representing activity of P450-1A2, -2C9, -2C19, -2D6, -2E1 and -3A. Gepirone and 1-PP produced negligible inhibition of all these reactions. Thus gepirone at therapeutic doses in humans has a low likelihood of inhibiting P450-mediated drug metabolism involving these cytochromes.

Molecular cloning and sequencing of cDNAs encoding insecticidal peptides from the primitive hunting spider, Plectreurys tristis (Simon).

Plectreurys tristis cephalothorax mRNA was isolated and amplified by PCR using degenerate primers corresponding to reverse translated mature Plt-VI toxin. An oligonucleotide corresponding to a portion of the amplified product was then used to screen a P. tristis cDNA library. The cDNAs from 10 positive clones were sequenced. Eight of these cDNAs corresponded to Plt-VI toxin, one to Plt-XI toxin, and one was very similar to Plt-VIII toxin, with the exception of a single amino acid substitution. Analysis of these cDNAs indicated that these toxins are initially synthesized as prepro-forms which undergo signal cleavage followed by additional processing at both their N- and C-termini to produce the mature products.

Accumulation of neuropeptides in the cerebral neurosecretory system of Manduca sexta larvae parasitized by the braconid wasp Cotesia congregata.

Fifth instar larvae of Manduca sexta that were parasitized by the braconid wasp Cotesia congregata failed to develop after the parasitoid larvae emerged, and these host larvae lingered for 2-3 weeks in a quiescent, nonfeeding state without initiating a larval molt or metamorphosis. This study was focused on the neuroendocrine changes associated with the host's developmental arrest. Immunohistochemical studies suggested that the host brain neurosecretory cells as well as their axon terminals in the corpora cardiaca-corpora allata complex accumulated multiple neuropeptides. The extent of accumulation in cells and axons increased with time, so that hosts examined 7-14 days after the wasps emerged showed the most intense staining with antibodies against prothoracicotropic hormone, bombyxin, allatotropin, allatostatin, diuretic hormone, eclosion hormone, proctolin, and FMRFamide. Increased levels of prothoracicotropic hormone and FMRFamide-like peptides in the brains of parasitized larvae were confirmed using Western blots and enzyme-linked immunosorbent assay (ELISA), respectively. Starvation of the unparasitized larvae induced some accumulation of the neuropeptides; however, the intensity of staining and number of immunopositive cells and axons were in most cases clearly higher in the parasitized larvae. Our results suggest that accumulation of the neuropeptides is associated with developmental arrest of parasitized larvae. Because a similar developmental arrest occurs in a wide range of parasitized insects, our findings may have relevance for many other species. Moreover, these data illustrate the potential value of using parasitized M. sexta larvae as a model for studying the mechanisms governing the rates of neuropeptide expression, processing, packaging, and release, as well as providing a rich source of neuropeptides, thus facilitating their isolation and characterization.

Characterization of the precursor for Manduca sexta diuretic hormone Mas-DH.

We have isolated a cDNA clone encoding a precursor form of the diuretic hormone from the tobacco hornworm Manduca sexta (Mas-DH). Translation of the cDNA revealed a 138-amino acid precursor consisting of the Mas-DH amino acid sequence bounded by dibasic amino acid processing sites, a putative signal sequence, and additional peptide sequence on either side of the Mas-DH coding sequence. The region of the precursor upstream of the mature Mas-DH sequence shows limited (28%) homology to the cryptic region of the ovine corticotropin-releasing factor precursor. The Mas-DH RNA is 1.5-1.6 kilobases long; it is present in both the heads and bodies of adult and larval insects. In prewandering fifth stadium larvae, Mas-DH mRNA is expressed in brain, nerve cord, gut, and Malpighian tubules, but not in the fat body. There is a single genomic copy of the Mas-DH gene; the message is multiply spliced.

Complete structure of eclosion hormone of Manduca sexta. Assignment of disulfide bond location.

The locations of the three disulfide bonds of eclosion hormone (EH) isolated from Manduca sexta were assigned by sequence analysis of thermolysin fragments and by comparison of a key heterodimeric fragment to regiospecifically synthesized parallel and antiparallel isomers. We elucidated the complete structure of Manduca EH as a 62-residue peptide which has three disulfide bonds between Cys14-Cys38, Cys18-Cys34, and Cys21-Cys49.

Frequency-specific auditory brainstem responses to bone-conducted stimuli.

The feasibility of recording bone-conducted auditory brainstem responses (ABRs) to 500-Hz and 2000-Hz tone bursts and clicks was investigated in normal-hearing adults. For all 3 stimuli, responses were detectable in all subjects at 30 dB nHL. At 20 dB nHL, the tone burst responses were detectable in 80-87% of the subjects, demonstrating that even the responses to 500-Hz tone bursts were relatively robust. Latencies and amplitudes of the responses were related to the stimuli. The cochlear locations contributing to the responses were investigated using high-pass masking. Derived-band analysis indicated reasonably good frequency specificity for the tone burst responses and a broad representation for the bone-conducted click, despite its lower frequency spectrum. The results of this study support the use of bone-conducted tone burst ABR for demonstrating frequency-specific normal cochlear sensitivity.

Identification of an allatostatin from the tobacco hornworm Manduca sexta.

A peptide (Manduca sexta allatostatin) that strongly inhibits juvenile hormone biosynthesis in vitro by the corpora allata from fifth-stadium larvae and adult females has been purified from extracts of heads of pharate adult M. sexta by a nine-step purification procedure. The primary structure of this 15-residue peptide has been determined: pGlu-Val-Arg-Phe-Arg-Gln-Cys- Tyr-Phe-Asn-Pro-Ile-Ser-Cys-Phe-OH, where pGlu is pyroglutamate). To our knowledge, this neuro-hormone has no sequence similarity with any known neuropeptide from other organisms. The synthetic free acid and amide forms showed in vitro activity indistinguishable from that of native M. sexta allatostatin. The ED50 of synthetic M. sexta allatostatin on early fifth stadium larval corpora allata in vitro was approximately 2 nM. This inhibition was reversible. In a cross-species study, M. sexta allatostatin also inhibited the corpora allata of adult female Heliothis virescens but had no effect on the activity of corpora allata of adult females of the beetle Tenebrio molitor, the grasshopper Melanoplus sanguinipes, or the cockroach Periplaneta americana.

Perilymphatic fistula: surgical experience in the United States.

One survey sent to 6953 individual otolaryngologic practices and 106 departments of otolaryngology at teaching hospitals in the United States, and a more limited survey of 75 patients operated on for perilymphatic fistula (PLF) at the House Ear Institute, addressed aspects of managing PLF: surgical incidence, reliability of diagnostic test, preoperative observations, and disability after surgery. Of surgeons sampled, 93% estimated incidence of PLF surgery to be less than or equal to 1 per 1000 otolaryngologic outpatient visits. The most reliable diagnostic indicators were history, symptomatology, and tympanometric and electronystagmographic fistula tests. About 72% of surgeons reported less than 4 weeks' average delay before surgery. Most surgeons and patients (greater than or equal to 70%) rated length of disability before return to work, exposure to noise, travel by airplane, swimming, and heavy lifting, at several weeks to several months. Diving was the most restricted activity. Results suggest that incidence of surgery and disability with PFL in the United States is very limited.

Isolation and identification of a diuretic hormone from the tobacco hornworm, Manduca sexta.

A diuretic hormone (DH) has been isolated from pharate adult heads of Manduca sexta by a nine-step purification procedure. The primary structure of the amino-terminal 40 residues was determined by sequence analysis of intact DH. The structure of an amidated carboxyl-terminal tryptic hexapeptide was characterized by sequence analysis of the peptide, and this hexapeptide was later compared by reversed-phase liquid chromatography with two synthetic hexapeptides with the free acid or amide at the carboxyl terminus. The complete structure of M. sexta DH was established as a 41-residue peptide without disulfide bonds: H-Arg-Met-Pro-Ser-Leu-Ser-Ile-Asp-Leu-Pro-Met-Ser-Val-Leu-Arg-Gln-Lys-Leu-Ser -Leu-Glu-Lys-Glu-Arg-Lys-Val-His-Ala-Leu-Arg-Ala-Ala-Ala-Asn-Arg-Asn-Phe-Leu- Asn-Asp-Ile-NH(2). M. sexta DH was synthesized and shown to have chromatographic and biological properties identical with those of the native material. Synthetic DH stimulated fluid excretion in vivo upon injection into larval M. sexta and newly emerged adult Pieris rapae. M. sexta DH has considerable sequence homology with corticotropin-releasing factor, urotensin I, and sauvagine.

Auditory brainstem responses and clinical follow-up of high-risk infants.

Auditory brainstem response (ABR) evaluations were performed on 667 high-risk infants from an infant special care unit. Of these infants, 82% passed the ABR. Those infants who failed the ABR were classified into two groups, those who failed at 30 dB hearing level and those who failed at 45 dB hearing level. All of the infants were encouraged to return for otologic/audiologic follow-up in 1, 3, or 6 months, depending on the initial ABR results. All of the infants with severe hearing impairments came from the group who failed at 45 dB hearing level. The incidence of severe sensorineural hearing impairment in this population was estimated to be 2.4%. For the group that failed at 30 dB hearing level, 80% of those who were abnormal at follow-up were considered to have conductive hearing disorders and 20% had mild sensorineural hearing impairments. In addition, infants enrolled in a parent-infant program for hearing impaired by 6 months of age were from the ABR program; however, several infants entered the parent-infant program at a relatively late age because they did not meet the high-risk criteria, they were from other hospitals, or they were not detected by the ABR program.

Identification of an allatotropin from adult manduca sexta.

A peptide that strongly stimulates the secretion of juvenile hormone from corpora allata in vitro (allatotropin) has been purified from extracts of heads of pharate adult Manduca sexta. The primary structure of this 13-residue peptide has been determined: H-Gly-Phe-Lys-Asn-Val-Glu-Met-Met-Thr-Ala-Arg-Gly-Phe-NH(2). This neurohormone has no sequence similarity with any known neuropeptide from other organisms. Synthetic allatotropin, as well as truncation fragments, including one with the five amino terminal residues deleted, showed in vitro activity indistinguishable from that of native allatotropin.

Perception of biomechanical motions by infants: implementation of various processing constraints.

Geometry informs us that there exist a large number of possible connectivity patterns consistent with a point-light display of a person walking. Yet there is only one pattern consistent with a "stick figure" representation of the human form, and that pattern is uniquely specified by those pairwise connections that remain locally rigid. In this study, sensitivity to local rigidity in biomechanical displays was investigated in 3- and 5-month-old infants. The results of Experiment 1 revealed that by 5 months of age, infants discriminate a locally rigid point-light walker display from one in which local rigidity is perturbed. In Experiment 2 we tested infants' sensitivity to the same stimuli when those stimuli were inverted. Contrary to the preceding experiment, the results revealed no evidence of discrimination. Taken together, these findings suggest that infants are sensitive to local rigidity in biomechanical displays but that this sensitivity is orientation specific. Possible mechanisms for this specificity are discussed in the context of additional constraints on the processing of biomechanical displays.

Isolation and primary structure of the eclosion hormone of the tobacco hornworm, Manduca sexta.

Eclosion hormone was isolated from trimmed pharate adult heads of Manduca sexta by an eight step purification procedure using a Heliothis virescens in vivo bioassay. The neuropeptide was active in second stadium M. sexta. The primary structure was determined by sequence analyses of the intact peptide and fragment peptides generated by lysyl endopeptidase, endoproteinase Glu-C, and proline-specific endopeptidase. The nature of the carboxyl terminus as a free acid was elucidated by analysis of amino acids from digestion of the intact peptide with lysyl endopeptidase, which liberated leucine, but no leucine amide. The complete primary structure of M. sexta closion hormone is H-Asn-Pro-Ala-Ile-Ala-Thr-Gly-Tyr-Asp-Pro-Met-Glu-Ile-Cys-Ile-Glu-Asn-Cy s-Ala- Gln-Cys-Lys-Lys-Met-Leu-Gly-Ala-Trp-Phe-Glu-Gly-Pro-Leu-Cys-Ala-Glu-Ser- Cys-Ile Lys-Phe-Lys-Gly-Lys-Leu-Ile-Pro-Glu-Cys-Glu-Asp-Phe-Ala-Ser-Ile-Ala-Pro- Phe-Leu-Asn-Lys-Leu-OH.

Acute hematogenous osteomyelitis of the epiphysis.

The case of an 11-year-old boy with acute hematogenous epiphyseal osteomyelitis is presented. Previous reported cases of epiphyseal osteomyelitis have been only of the subacute type. This case is presented to emphasize that osteomyelitis can occur in the epiphysis and reinforce the need for early diagnosis.

Posterior strut fusions to enhance immediate postoperative cervical stability.

UNLABELLED: In an attempt to enhance the immediate stability of posterior interspinous fusion constructs, the authors conducted the following project. Twenty-four adult mongrel dogs underwent a posterior C4-C5 fusion using iliac crest autogenous graft and internal fixation using either ulna struts (12) or metallic struts (12) fixed into position by sublaminar wires. Half of the animals were killed at either 1 week or 3 months postoperatively, and their C4-C5 motion segments were excised and studied radiologically, mechanically, and histologically. Both fusions created immediate and 3-month stability equivalent or superior to normal C4-C5 canine spinal segments. However, three dogs were rendered completely and two dogs incompletely quadriplegic by the surgery. CLINICAL RELEVANCE: Because of the relatively high rate of neurologic injury associated with these procedures in normal dogs, the authors hesitate to endorse their use in all but complete quadriplegic patients.

Isolation and primary structure of two peptides with cardioacceleratory and hyperglycemic activity from the corpora cardiaca of Periplaneta americana.

Two cardioacceleratory peptides from the corpora cardiaca of Periplaneta americana have been purified by gel filtration and reversed-phase liquid chromatography, Based on analysis of the intact factors and their chymotryptic fragments, we have assigned the primary structure of these octapeptides as pGlu-Val-Asn-Phe-Ser-Pro-Asn-Trp-NH2, designated periplanetin CC-1, and pGlu-Leu-Thr-Phe-Thr-Pro-Asn-Trp-NH2, designated periplanetin CC-2. They represent new members of a family of invertebrate peptides that includes locust adipokinetic hormone and crustacean red-pigment concentrating hormone. Both peptides show adipokinetic activity in grasshoppers and hyperglycemic activity in cockroaches. One of these peptides (CC-2) has provocative sequence homology with the NH2-terminal portion of glucagon.

Forward masking of auditory nerve and brainstem responses using high-pass noise maskers.

The effects of varying the low-frequency cutoff of a high-pass noise used as a forward masker for a broadband click (40 dB HL) are compared for wave V of the auditory brainstem response and N1 from the ear canal. Derived responses were also obtained using a waveform subtraction technique. N1 amplitude and wave V latency were most sensitive to the changes in the masker low-frequency cutoff. Results suggest that N1 is biased toward the high frequencies, most likely because of its requirements for high neural synchrony, and is not necessarily related to the maximum area of excitation. Wave V, on the other hand, seems to be less dependent upon highly synchronous events and is more closely related to activity in the mid-to-lower frequencies. Complex behavior of wave V was observed as a function of delta T which suggests that temporal as well as spatial factors can interact in their contributions to wave V.

Forward masking of auditory nerve (N1) and brainstem (wave V) responses in humans.

Wave V of the auditory brainstem response and N1 from the ear canal were recorded from normal hearing adults using a forward masking paradigm. Response amplitudes and latencies to 40 dB HL probe clicks presented in quiet and as a function of the time delay (delta T) following short-duration wideband noise maskers were measured. The masking effects for wave V were different than for N1. The primary effects were decreases in N1 amplitude and increases in wave V latency, neither of which were recovered by delta T = 100 ms. The V-N1 latency interval increased for delta Ts below 50 ms. Wave V amplitude was fully recovered by delta T = 25 ms, even though N1 amplitude was significantly reduced. Recovery functions are also described for some variations in masker duration and masker level. Results are explainable in terms of peripheral and central processes or entirely peripheral processes. The differential effects of N1 and wave V suggest, at least for some stimulus conditions, that these two responses are to some degree independent of each other.