bluuebunny/crossref_metadata_2025 huggingface dataset:
Residual feed intake adjusted for backfat thickness and feeding frequency is independent of fertility in beef heifers
Authors: Basarab J. A. , Colazo M. G. , Ambrose D. J. , Novak S. , McCartney D. , Baron V. S.
Published: January 2012

Basarab, J. A., Colazo, M. G., Ambrose, D. J., Novak, S., McCartney, D. and Baron, V. S. 2011. Residual feed intake adjusted for backfat thickness and feeding frequency is independent of fertility in beef heifers. Can. J. Anim. Sci. 91: 573–584. This study examined the effects of residual feed intake (RFI), RFI adjusted for off-test backfat thickness (RFIfat) and RFI adjusted for off-test backfat thickness and feeding event frequency (RFIfat & activity) on heifer fertility and productivity. Beef heifers (n=190) were monitored for individual daily feed intake and feeding event activity over 108–112 d using the GrowSafe System® and assessed for age at puberty based on plasma progesterone concentration. Individual animal daily feed intake, feeding event activity and off-test backfat thickness were then used to calculate RFI, RFIfat and RFIfat & activity and group heifers as either negative ([−], RFI<0.0) or positive ([+], RFI≥0.0) for RFI. Heifers averaged 298 kg (SD=34) in body weight, were 276 days of age (SD=19) at the start of test, grew at 0.90 kg d−1 (SD=0.21), consumed 7.62 kg DM head−1 d−1 (SD=0.84) and had a feed conversion ratio of 8.93 (SD=2.43). Age (351 d, SD=43) and weight (367.3 kg, SD=45.0) at puberty were similar between [−] and [+] RFI heifers, but age at puberty was delayed in [−] RFIfat (P=0.04) and RFIfat & activity (P=0.08) heifers compared with [+] RFIfat and RFIfat & activity heifers. Efficient or [−] RFI heifer exhibited a lower pregnancy (76.84 vs. 86.32%, P=0.09) and calving rate (72.63 vs. 84.21%, P=0.05) compared with [+] RFI heifers. These differences were partially removed in [−] RFIfat and completely removed in [−] RFIfat & activity compared with their [+] RFI counterparts (pregnancy rate, 80.85 vs. 82.29%, P=0.80; calving rate, 75.53 vs. 81.25%, P=0.34). No differences were observed between efficient and inefficient heifers in calving difficulty, average calving date, age at first calving, calf birth weight, calf pre-weaning ADG, calf weaning weight and heifer productivity. However, [+] RFI heifers exhibited a 1.9-fold higher calf death loss compared with [−] RFI heifers (11.11% vs. 5.71%, P=0.24). This difference was more pronounced in [+] RFIfat and [+] RFIfat & activity heifers, which exhibited 2.2-fold (11.84% vs. 5.33%, P=0.15) and 3.0-fold (12.66% vs. 4.17%, P=0.06) higher calf death loss compared with [−] RFI heifers. There was no relationship of RFI adjusted for backfat thickness and feeding activity on fertility traits indicating that backfat thickness and feeding activity may be associated with feed intake and should be considered when selecting heifers for improved feed efficiency.
Performance, feeding behaviour and rumen pH profile of beef cattle fed corn silage in combination with barley grain, corn or wheat distillers’ grain or wheat middlings
Authors: Holtshausen L. , Beauchemin K.A. , Schwartzkopf-Genswein K.S. , González L.A. , McAllister T.A. , Gibb D.J.
Published: January 2012

Holtshausen, L., Beauchemin, K. A., Schwartzkopf-Genswein, K. S., González, L. A., McAllister, T. A. and Gibb, D. J. 2011. Performance, feeding behaviour and rumen pH profile of beef cattle fed corn silage in combination with barley grain, corn or wheat distillers’ grain or wheat middlings. Can. J. Anim. Sci. 91: 703–710. This study compared growth performance, feeding behaviour and ruminal pH profile of growing beef heifers fed a total mixed ration (TMR) containing corn silage and either [400 g kg−1 dry matter (DM)] barley grain (CTL), corn dried distillers’ grain with solubles (CDDGS), wheat dried distillers’ grain with solubles (WDDGS) or wheat middlings (WM). Eighty beef heifers (16 ruminally cannulated; 301±34 kg) were blocked by weight and randomly assigned to eight feedlot pens for a 70-d backgrounding study. Pens were randomly assigned to one of four dietary treatments and equipped with the GrowSafe feed intake system for determining individual feed intake and monitoring feeding behaviour. Dry matter intake (DMI) was lower (P<0.01) and average daily gain (ADG) tended to be lower for CTL (P=0.06) heifers as compared with heifers on other treatments. Feed conversion efficiency (i.e., gain to feed ratio; P=0.41) and feeding behaviour and ruminal pH profile measurements (P>0.05) did not differ among treatments. This study illustrates that barley grain can be replaced by corn dried distillers’ grain, wheat dried distillers’ grain or wheat middlings in diets fed to growing beef cattle without compromising feed conversion efficiency, adversely affecting feeding behaviour (e.g., decreased meal frequency and duration) or increasing the incidence of ruminal acidosis.
Removal of supplemental vitamin A from barley-based diets improves marbling in feedlot heifers
Authors: Gibb D. , Van Herk F. H. , Mir P. , Loerch S. , McAllister T.
Published: January 2012

Gibb, D. J., Van Herk, F. H., Mir, P. S., Loerch, S. and McAllister, T. A. 2011. Removal of supplemental vitamin A from barley-based diets improves marbling in feedlot heifers. Can. J. Anim. Sci. 91: 669–674. The objective of this research was to determine if removing supplemental vitamin A from barley-based feedlot diets affects animal performance, health, or carcass quality. Six pens per treatment (10 heifers per pen) were randomly assigned to receive zero (–VA) or 3640 (+VA) IU kg−1 dry matter of supplemental vitamin A in barley-based feedlot diets. Initial serum retinol was similar between treatments (28 µg dL−1; P=0.34), but –VA reduced levels by 40% (30 vs. 50 µg dL−1; P<0.001) by day 217. Removal of supplemental vitamin A reduced dry matter intake during the 58 d backgrounding period (6.93 vs. 7.07 kg d−1; P=0.007) and over the 218-d trial (9.18 vs. 9.35 kg d−1; P<0.001), but had no effect on average daily gain during backgrounding (1.22 kg d−1; P=0.46) or over all (1.46 kg d−1; P=0.15). Based on camera grading, –VA increased degree of marbling (480.6 vs. 439.3; P=0.02) without affecting backfat thickness (0.74 cm; P=0.62). Ultrasound measurements were highly correlated with camera grading, but did not detect treatment difference in marbling score (P=0.99). Results from this study show that the removal of supplemental vitamin A increased marbling without affecting backfat, gains, or animal health.
An evaluation of corticotropin-releasing hormone and leptin SNPs relative to cattle behaviour
Authors: Pugh K. A. , Stookey J. M. , Buchanan F. C.
Published: January 2012

Pugh, K. A., Stookey, J. M. and Buchanan, F. C. 2011. An evaluation of corticotropin-releasing hormone and leptin SNPs relative to cattle behaviour. Can. J. Anim. Sci. 91: 562–572. The purpose of this study was to identify associations between single nucleotide polymorphisms (SNPs) in two genes involved in the hypothalamic-pituitary-adrenal axis and growth, namely corticotropin-releasing hormone (CRH), and leptin (LEP), and measurements of temperament in beef cattle. Four hundred crossbred beef steers were evaluated upon entry into a beef facility using several different measurements of response to handling: subjective score (SS), strain gauge (SG), movement measurement device (MMD) and exit time (ET). The steers were genotyped at the CRH 22C>G, CRH 240C>G and LEP 73C>T SNPs by PCR-RFLP. The SNP genotypes and two-way interactions between LEP and each CRH SNP were analyzed as effects on the various temperament measurements. We found interactions between CRH 22C>G and LEP and CRH 240C>G and LEP with SG. Within this interaction there appears to be a positive effect of one CRH allele (C) within LEP TT animals while in LEP CC the other CRH allele (G) had a positive effect. These interactions, especially between CRH 22C>G and LEP, needs to be confirmed in other populations of beef cattle. It may be possible in the future to select for temperament alongside production goals.
Oxidative stability in grinds from omega-3 enhanced pork
Authors: Juárez M. , Dugan M. E. R. , Larsen I. L. , Thacker R. , Rolland D. C. , Aalhus J. L.
Published: January 2012

Juárez, M., Dugan, M. E. R., Larsen, I. L., Thacker, R., Rolland, D. C. and Aalhus, J. L. 2011. Oxidative stability in grinds from omega-3 enhanced pork. Can. J. Anim. Sci. 91: 623–634. In order to investigate the effect of enhancing n-3 fatty acid levels in carcasses on the retail and sensory characteristics of pork grinds, as well as the ability of increasing dietary levels of vitamin E to stabilize the increase in PUFA levels from flaxseed supplementation, 81 pigs were used in a 3×3 factorial experiment. Dietary treatments included three lengths of time (0, 3 and 6 wk) of flaxseed supplementation and three levels of vitamin E (40, 200 and 400 mg kg feed−1). α-Tocopherol tissue levels increased with dietary vitamin E supplementation (P<0.001), and fat softness (P=0.018) and total PUFA and n-3 fatty acids (P<0.001) increased with flaxseed supplementation. Most other animal performance, carcass and lean pork quality traits were not affected (P>0.05) by dietary treatments. In ground pork, the increase in TBARS after 6 d in retail was lower (P<0.001) with increasing dietary vitamin E levels. However, vitamin E had no effect (P>0.05) on the higher (P<0.001) TBARS levels observed in grinds from flaxseed fed pigs. The dietary addition of flaxseed negatively modified (P<0.05) all the sensory attributes of both cooked and reheated products. Increasing the fat content of the grinds up to 30% seemed to counteract (P>0.05) the negative effects of feeding flaxseed for 3 wk. Feeding vitamin E was not able to prevent negative effects (P<0.05) observed during retail display in grinds with either increasing fat content or higher n-3 fatty acids from dietary flaxseed. However, increasing dietary vitamin E only showed a protective effect (P<0.05) on retail appearance after long periods of ageing.
Arteriovenous Malformation Pinna: Review of Literature
Authors: Goel Anuj Kumar
Published: January 2012

Arteriovenous malformations are rare in the head and neck region and generally arise from intracranial vessels. We present a rare case of arteriovenous malformation related to pinna. The role of color Doppler sonography in the diagnosis and management of such case is discussed along with review of literature.
Pain Control in Head and Neck Cancer
Authors: Alroosan Motassim , Alroosan Afaf
Published: January 2012

Objective

To describe the treatment of head and neck cancer pain in KHMC and to evaluate the predictive factors for inadequate management between April 2007 and March 2010.

Subjects

Twenty-five patients with head and neck cancer.

Main measures

Patients rated prevalence and severity of pain and functional impairment related to pain. Doctors reported patients’ cancer characteristic, performance status, pain severity, and analgesic drugs ordered.

Results

57% (14/25) of patients with cancer reported pain due to their disease, and, of those with pain, 69% (9/13) rated their worst pain at a level that impaired their ability to function. 30% (5/12) were reported as receiving no drugs for their pain. Of the 18 patients in pain for whom information on treatment was available 51% (41/18) were not receiving adequate pain reliefs, according to an index based on the World Health Organization's guidelines. Doctors were found to underestimate the severity of their patients’ pain. Younger patients, patients without metastasis disease, patients with a better performance status, and patients who rated their pain as more severe than their doctors did were at greater risk for under treatment of their pain.

Conclusion

In the light of the high prevalence and the severity of pain among patients with head and neck cancer, the assessment and treatment of cancer pain was inadequate, emphasizing the need for changes in patient care.
Otogenic Anterior Chest Wall Abscess: A Rare and Unique Presentation of Bezold's Abscess
Authors: Agrawal Arti , Singh Hitendra Prakash , Kumar Dharmendra
Published: January 2012

In the era of antibiotics, deep neck abscess is a rare complication of acute mastoiditis. Bezold's abscess, the most common cause of the otogenic deep neck abscess in preantibiotic era, is a rare complication of mastoiditis nowadays and it should be considered in the differential diagnosis of neck abscesses as well as unexplained intracranial/extracranial or upper thoracic abscesses. We report a case of 20-year old female with an abscess over anterior chest wall as a sequele of bezold's abscess which was a complication of cholesteatoma with mastoiditis.
Orofacial Impactions: A Common Rarity
Authors: Karjodkar Freny , Khanna Sunali , Patil Darshana
Published: January 2012

Impactions of the orofacial region are rare but impactions of the mobile tongue are unique. Hence, very limited literature is available. Foreign bodies embedded in the maxillofacial region frequently result from trauma and dental treatment. This is a compilation of cases of tongue impaction, tooth in maxillary sinus and watch battery impacted in tooth. A brief insight into the incidence of orofacial impactions, radiographic investigations and management is also provided.
Inflammatory Pseudotumor of Premaxillary Subcutaneous Tissue
Authors: Gawai Sujata A , Kumar Kalpana R , Sangole Vaishali S , Rao Suman P , George Divya A
Published: January 2012

Inflammatory pseudotumor also known as plasma cell granuloma is a space occupying lesion which occurs in wide variety of somatic tissue and visceral organs, including lungs, liver, thyroid and many other organs. Recently, it has been described in the major salivary glands and buccal tissue in children.1 We have described here the clinical, radiological and histological findings of inflammatory pseudotumor in premaxillary subcutaneous tissue in an adult, which is a rare site.
Brain Metastases Secondary to Advanced Laryngeal Cancer Presenting as Diminution of Vision and Lower Limb Weakness
Authors: Ahmad Rauf , Hussain Syed Majid , Ahmad Mukhtar
Published: January 2012

Objective

Intracranial metastases from primary laryngeal carcinoma are extremely rare and to present as diminution of vision has not been reported in published English literature. We present a case of advanced laryngeal carcinoma, who after treatment with surgery and chemo radiation, presented with decreased vision and weakness of lower limbs secondary to brain metastases.

Case report

A 35-year-old male presented with dysphonia and L upper neck swelling. Endoscopy revealed a left supraglottic mass with fixed vocal cord and pathology of primary site and neck swelling reported it as moderately differentiated squamous cell carcinoma. Clinical and radiological assessment staged the tumor as T3N2bM0. Patient underwent combined standard surgical and medical treatment. Eight months after completion of treatment patient presented as decreased visual acuity (R > L) and gradually progressing weakness of lower limbs. Evidence of papilloedema on fundus exam prompted an urgent CT brain which showed multiple metastatic deposits in brain. There was no evidence of metastases in lungs, bones or liver.

Conclusion

Brain metastases are a known entity in Head and Neck cancer. Larynx as a primary site for the same should be kept in consideration with an atypical presentation as in present case.
An Unusual Presentation of Nasal Polyp Arising from Floor of Nasal Cavity
Authors: Naik Mahendra S , Naik Sulabha M
Published: January 2012

Introduction

Nasal polyps are pedunculated, edematous, prolapsed mucosa of the paranasal sinuses. These polyps commonly arise around the ostia of the paranasal sinuses in the middle meatus.

Discussion

The commonest sites of polyp formation are the ethmoid sinuses and maxillary sinus. Rarely polyps may also arise from the other paranasal sinuses. Sites in the nasal mucosa other than the paranasal sinuses are very rare, though polyps arising from the septum have also been reported.

The etiology of nasal polyposis is believed to be due to an inflammatory reaction of the nasal and paranasal sinus mucosa.

Conclusion

In addition to the theory of altered airway dynamics in the middle meatus, there also appears to be a link between polyp formation and preceding chronic inflammation. This is the most likely explanation for the origin of polyps in unusual sites.

We present here a case of a nasal polyp arising from the floor of the nasal cavity. There are no previous records or reports in literature of this unusual site of origin of a nasal polyp.
Primary Orbital Hydatid Cyst
Authors: Baser Brajendra , Kothari Shenal , Thatte Shreya , Munjal Vishal , Kinger Arvind
Published: January 2012

The authors want to highlight the importance of clinical, radiological and histopathological evaluation in unilateral proptosis. A 17-yearold male presented with left progressive nonpulsatile proptosis, lateral gaze diplopia and decreased visual acuity. It was diagnosed as orbital hydatid cyst on CT scan and MRI. The patient was successfully operated with near total recovery of the vision. Radiological investigation showed a circumscribed cystic lesion lateral to orbit separate from the lacrimal gland. Intraoperative cysts and postoperative histopathology confirmed the primary orbital hydatid cyst.

Although rare there is always a possibility of a primary hydatid in patients with unilateral proptosis, restricted eye movements and lateral decreased visual acuity. This is possible even when the Casoni's test is negative. Surgical excision with postoperative albendazole is the effective treatment for the cure of disease.
Direct and semi-direct radiative forcing of smoke aerosols over clouds
Authors: Wilcox E. M.
Published: January 2012

Abstract. Observations from Earth observing satellites indicate that dark carbonaceous aerosols that absorb solar radiation are widespread in the tropics and subtropics. When these aerosols mix with clouds, there is generally a reduction of cloudiness owing to absorption of solar energy in the aerosol layer. Over the subtropical South Atlantic Ocean, where smoke from savannah burning in southern Africa resides above a persistent deck of marine stratocumulus clouds, radiative heating of the smoke layer leads to a thickening of the cloud layer. Here, satellite observations of the albedo of overcast scenes of 25 km2 size or larger are combined with additional satellite observations of clouds and aerosols to estimate the top-of-atmosphere direct radiative forcing attributable to presence of dark aerosol above bright cloud, and the negative semi-direct forcing attributable to the thickening of the cloud layer. The average positive direct radiative forcing by smoke over an overcast scene is 9.2±6.6 W m−2 for cases with an unambiguous signal of absorbing aerosol over cloud in passive ultraviolet remote sensing observations. However, cloud liquid water path is enhanced by 16.3±7.7 g m−2 across the range of values for sea surface temperature for cases of smoke over cloud. The negative radiative forcing associated with this semi-direct effect of smoke over clouds is estimated to be −5.9±3.5 W m−2. Therefore, the cooling associated with the semi-direct cloud thickening effect compensates for greater than 60 % of the direct radiative effect. Accounting for the frequency of occurrence of significant absorbing aerosol above overcast scenes leads to an estimate of the average direct forcing of 1.0±0.7 W m−2 contributed by these scenes averaged over the subtropical southeast Atlantic Ocean during austral winter. The regional average of the negative semi-direct forcing is −0.7±0.4 W m−2. Therefore, smoke aerosols overlaying the decks of overcast marine stratocumulus clouds considered here yield a small net positive radiative forcing, which results from the difference of two larger effects.
Attribution and evolution of ozone from Asian wild fires using satellite and aircraft measurements during the ARCTAS campaign
Authors: Dupont R. , Pierce B. , Worden J. , Hair J. , Fenn M. , Hamer P. , Natarajan M. , Schaack T. , Lenzen A. , Apel E. , Dibb J. , Diskin G. , Huey G. , Weinheimer A. , Kondo Y. , Knapp D.
Published: January 2012

Abstract. We use ozone and carbon monoxide measurements from the Tropospheric Emission Spectrometer (TES), model estimates of Ozone, CO, and ozone pre-cursors from the Real-time Air Quality Modeling System (RAQMS), and data from the NASA DC8 aircraft to characterize the source and dynamical evolution of ozone and CO in Asian wildfire plumes during the spring ARCTAS campaign 2008. On the 19 April, NASA DC8 O3 and aerosol Differential Absorption Lidar (DIAL) observed two biomass burning plumes originating from North-Western Asia (Kazakhstan) and South-Eastern Asia (Thailand) that advected eastward over the Pacific reaching North America in 10 to 12 days. Using both TES observations and RAQMS chemical analyses, we track the wildfire plumes from their source to the ARCTAS DC8 platform. In addition to photochemical production due to ozone pre-cursors, we find that exchange between the stratosphere and the troposphere is a major factor influencing O3 concentrations for both plumes. For example, the Kazakhstan and Siberian plumes at 55 degrees North is a region of significant springtime stratospheric/tropospheric exchange. Stratospheric air influences the Thailand plume after it is lofted to high altitudes via the Himalayas. Using comparisons of the model to the aircraft and satellite measurements, we estimate that the Kazakhstan plume is responsible for increases of O3 and CO mixing ratios by approximately 6.4 ppbv and 38 ppbv in the lower troposphere (height of 2 to 6 km), and the Thailand plume is responsible for increases of O3 and CO mixing ratios of approximately 11 ppbv and 71 ppbv in the upper troposphere (height of 8 to 12 km) respectively. However, there are significant sources of uncertainty in these estimates that point to the need for future improvements in both model and satellite observations. For example, it is challenging to characterize the fraction of air parcels from the stratosphere versus those from the fire because of the low sensitivity of the TES CO estimates used to mark stratospheric air versus air parcels affected by the smoke plume. Model transport uncertainties, such as too much dispersion, results in a broad plume structure from the Kazakhstan fires that is approximately 2 km lower than the plume observed by aircraft. Consequently, the model and TES data do not capture the photochemical production of ozone in the Kazakhstan plume that is apparent in the aircraft in situ data. However, ozone and CO distributions from TES and RAQMS model estimates of the Thailand plume are within the uncertainties of the TES data. Therefore, the RAQMS model is better able to characterize the emissions from this fire, the mixing of ozone from the stratosphere to the plume, and the photochemical production and transport of ozone and ozone pre-cursors as the plume moves across the Pacific.
Nucleation and growth of sulfate aerosol in coal-fired power plant plumes: sensitivity to background aerosol and meteorology
Authors: Stevens R. G. , Pierce J. R. , Brock C. A. , Reed M. K. , Crawford J. H. , Holloway J. S. , Ryerson T. B. , Huey L. G. , Nowak J. B.
Published: January 2012

Abstract. New-particle formation in the plumes of coal-fired power plants and other anthropogenic sulfur sources may be an important source of particles in the atmosphere. It remains unclear, however, how best to reproduce this formation in global and regional aerosol models with grid-box lengths that are 10s of kilometers and larger. The predictive power of these models is thus limited by the resultant uncertainties in aerosol size distributions. In this paper, we focus on sub-grid sulfate aerosol processes within coal-fired power plant plumes: the sub-grid oxidation of SO2 with condensation of H2SO4 onto newly-formed and pre-existing particles. We have developed a modeling framework with aerosol microphysics in the System for Atmospheric Modelling (SAM), a Large-Eddy Simulation/Cloud-Resolving Model (LES/CRM). The model is evaluated against aircraft observations of new-particle formation in two different power-plant plumes and reproduces the major features of the observations. We show how the downwind plume aerosols can be greatly modified by both meteorological and background aerosol conditions. In general, new-particle formation and growth is greatly reduced during polluted conditions due to the large pre-existing aerosol surface area for H2SO4 condensation and particle coagulation. The new-particle formation and growth rates are also a strong function of the amount of sunlight and NOx since both control OH concentrations. The results of this study highlight the importance for improved sub-grid particle formation schemes in regional and global aerosol models.
Aerosol direct radiative forcing based on GEOS-Chem-APM and uncertainties
Authors: Ma X. , Yu F. , Luo G.
Published: January 2012

Abstract. Aerosol direct radiative forcing (DRF) plays an important role in global climate change but has a large uncertainty. Here we investigate aerosol DRF with GEOS-Chem-APM, a recently developed global aerosol microphysical model that is designed to capture key particle properties (size, composition, coating of primary particles by volatile species, etc.). The model, with comprehensive chemistry, microphysics and up-to-date emission inventories, is driven by assimilated meteorology, which is presumably more realistic compared to the model-predicted meteorology. For this study, the model is extended by incorporating a radiation transfer model. Optical properties are calculated using Mie theory, where the core-shell configuration could be treated with the refractive indices from the recently updated values available in the literature. The surface albedo is taken from MODIS satellite retrievals for the simulation year, in which the data set for the 8-day mean at 1 km resolution for 7 wavebands is provided. We derive the total and anthropogenic aerosol DRF, mainly focus on the results of anthropogenic aerosols, and then compare with those values reported in previous studies. In addition, we examine the anthropogenic aerosol DRF's dependence on several key factors, including the particle size of black carbon (BC) and primary organic carbon (POC), the density of BC and the mixing state. Our studies show that the anthropogenic aerosol DRF at top of atmosphere (TOA) for all sky is −0.41 W m−2. However, the sensitivity experiments suggest that the magnitude could vary from −0.08 W m−2 to −0.61 W m−2 depending on assumptions regarding the mixing state, size and density of particles.
AMS and LC/MS analyses of SOA from the photooxidation of benzene and 1,3,5-trimethylbenzene in the presence of NOx: effects of chemical structure on SOA aging
Authors: Sato K. , Takami A. , Kato Y. , Seta T. , Fujitani Y. , Hikida T. , Shimono A. , Imamura T.
Published: January 2012

Abstract. Oxygenated organic aerosol (OOA) observed in remote areas is believed to comprise aged secondary organic aerosol (SOA); however, the reaction processes relevant to SOA aging have hitherto been unclear. We recently measured the mass spectra of SOA formed from the photooxidation of aromatic hydrocarbons using an Aerodyne aerosol mass spectrometer (AMS), and reported that SOA aging is slowed with increasing number of alkyl groups in the precursor molecule. In this study, we attempted to select benzene and 1,3,5-trimethylbenzene (TMB) as precursors to analyze SOA formed from the photooxidation of aromatic hydrocarbons in the presence of NOx using high-resolution time-of-flight AMS (H-ToF-AMS) and liquid chromatography/time-of-flight mass spectrometry (LC/TOF-MS). A van Krevelen diagram was studied using the O/C and H/C ratios obtained by H-ToF-AMS for organics present in SOA. The results showed these organics to be rich in carboxylic acids or hydroxycarbonyls, and the O/C ratio of SOA formed by the reaction of 1,3,5-TMB to be lower than that for benzene. Analytical results from LC/TOF-MS showed the particulate products formed by the reaction of 1,3,5-TMB to be richer in ketocarboxylic acids than for benzene. These results indicate that SOA aging proceeds mainly by formation of carboxylic acids, and that the rate of SOA aging in laboratory chambers is limited by the oxidation of ketone groups. SOA formed in laboratory chamber experiments is less oxidized than for ambient OOA, not only because the experimental duration is insufficient. Laboratory chamber experiments are not able to simulate ketocarboxylic acid photochemical oxidation in the aqueous phase. Further, it was newly found that, unlike the reaction of benzene, only very small amounts of nitrophenols are produced by the reaction of 1,3,5-TMB.
Microbial community diversity of the eastern Atlantic Ocean reveals geographic differences
Authors: Friedline C. J. , Franklin R. B. , McCallister S. L. , Rivera M. C.
Published: January 2012

Abstract. Prokaryotic communities are recognized as major drivers of the biogeochemical processes in the oceans. However, the genetic diversity and composition of those communities is poorly understood. The aim of this study was to investigate the eubacterial communities in three different water layers: surface (2–20 m), deep chlorophyll maximum (DCM; 28–90 m), and deep (100–4600 m) at nine stations along the eastern Atlantic Ocean from 42.8° N to 23.7° S. In order to describe the dynamics of the eubacterial assemblages in relation to depth, associated environmental properties, and Longhurstian ecological provinces community DNA was extracted from 16 samples, from which the V6 region of 16s rDNA was PCR-amplified with eubacteria-specific primers, and the PCR amplicons were pyrosequenced. A total of 352 029 sequences were generated; after quality filtering and processing, 257 260 sequences were clustered into 2871 normalized Operational Taxonomic Units (OTU) using a definition of 97% sequence identity. Comparisons of the phylogenetic affiliation of those 2871 OTUs show more than 54% of them were assigned to the Proteobacteria, with the Alphaproteobacteria representing 4% of the total Proteobacteria OTUs, and the Gammaproteobacteria representing 22%. Within the Alphaproteobacteria-affiliated OTUs, 44% of the OTUs were associated with the ubiquitous SAR11 clade. The phylum Cyanobacteria represent 10% of the reads, with the majority of those reads among the GpIIa family including Prochlorococcus and Synechococcus. Among the Gammaproteobacteria, a single OTU affiliated to Alteromonas comprises ~3% of the abundance. The phyla Bacteroidetes, Verrucomicrobia, Actinobacteria, and Firmicutes represent approximately 7%, 0.8%, 2%, and 0.05% of the read abundance, respectively. Community ecology statistical analyses and a novel implementation of Bayesian inference suggests that eastern Atlantic Ocean eubacterial assemblages are vertically stratified and associated with water layers characterized by unique environmental signals (e.g., temperature, salinity, and nutrients). Genetic composition of eubacterial communities from the same water layer are more similar to each other than to the communities from different water layers. Moreover, within the same water layer the separation of the communities appears to show a significant distance effect. Surface eubacterial communities displayed a general congruency with the ecological provinces defined by Longhurst with exceptions usually associated with unique hydrographic and biogeochemical features. Collectively, our findings suggest that a vertical and latitudinal biogeographical signature is present in the studied communities and that both environmental parameters and ecological provinces are drivers of eubacterial assemblages in the eastern Atlantic Ocean.
Deglaciation records of 17O-excess in East Antarctica: reliable reconstruction of oceanic normalized relative humidity from coastal sites
Authors: Winkler R. , Landais A. , Sodemann H. , Dümbgen L. , Prié F. , Masson-Delmotte V. , Stenni B. , Jouzel J.
Published: January 2012

Abstract. We measured δ17O and δ18O in two Antarctic ice cores at EPICA Dome C (EDC) and TALDICE (TD), respectively, and computed 17O-excess with respect to VSMOW. The comparison of our 17O-excess data with the previous record obtained at Vostok (Landais et al., 2008a) revealed differences up to 35 ppm in 17O-excess mean level and evolution for the three sites. Our data show that the large increase depicted at Vostok (20 ppm) during the last deglaciation is a regional and not a general pattern in the temporal distribution of 17O-excess in East Antarctica. The EDC data display an increase of 12 ppm, whereas the TD data show no significant variation from the Last Glacial Maximum (LGM) to the Early Holocene (EH). A Lagrangian moisture source diagnostic revealed very different source regions for Vostok and EDC compared to TD. These findings combined with the results of a sensitivity analysis, using a Rayleigh-type isotopic model, suggest that normalized relative humidity (RHn) at the oceanic source region (OSR) is a determining factor for the spatial differences of 17O-excess in East Antarctica. However, 17O-excess in remote sites of continental Antarctica (e.g. Vostok) may be highly sensitive to local effects. Hence, we consider 17O-excess in coastal East Antarctic ice cores (TD) to be more reliable as a proxy for RHn at the OSR.
A modelling approach to assessing the timescale uncertainties in proxy series with chronological errors
Authors: Divine D. V. , Godtliebsen F. , Rue H.
Published: January 2012

Abstract. The paper proposes an approach to assessment of timescale errors in proxy-based series with chronological uncertainties. The method relies on approximation of the physical process(es) forming a proxy archive by a random Gamma process. Parameters of the process are partly data-driven and partly determined from prior assumptions. For a particular case of a linear accumulation model and absolutely dated tie points an analytical solution is found suggesting the Beta-distributed probability density on age estimates along the length of a proxy archive. In a general situation of uncertainties in the ages of the tie points the proposed method employs MCMC simulations of age-depth profiles yielding empirical confidence intervals on the constructed piecewise linear best guess timescale. It is suggested that the approach can be further extended to a more general case of a time-varying expected accumulation between the tie points. The approach is illustrated by using two ice and two lake/marine sediment cores representing the typical examples of paleoproxy archives with age models based on tie points of mixed origin.
Simulations over South Asia using the weather research and forecasting model with chemistry (WRF-Chem): chemistry evaluation and initial results
Authors: Kumar R. , Naja M. , Pfister G. G. , Barth M. C. , Wiedinmyer C. , Brasseur G. P.
Published: January 2012

Abstract. This study presents annual simulations of tropospheric ozone and related species made for the first time using the WRF-Chem model over South Asia for the year 2008. The model simulated ozone, CO, and NOx are evaluated against ground-based, balloon-borne and satellite-borne (TES, OMI and MOPITT) observations. The comparison of model results with surface ozone observations from seven sites and CO and NOx observations from three sites, indicate the model's ability in reproducing seasonal variations of ozone and CO, but show some differences in NOx. The modeled vertical ozone distribution agrees well with the ozone soundings data from two Indian sites. The vertical distributions of TES ozone and MOPITT CO are generally well reproduced, but the model underestimates TES ozone, OMI tropospheric column NO2 and MOPITT total column CO retrievals during all the months except MOPITT retrievals during August–January. Largest differences between modeled and satellite retrieved quantities are found during spring when intense biomass burning activity occurs in this region. The evaluation results indicate large uncertainties in anthropogenic and biomass burning emission estimates, especially for NOx. The model results indicate clear regional differences in the seasonality of surface ozone over South Asia with estimated net ozone production during daytime (11:30–15:30 h) over inland regions of 0–5 ppbv h−1 during all seasons and of 0–2 ppbv h−1 over marine regions during outflow periods. The model results indicate that ozone production in this region is mostly NOx-limited. This study shows that WRF-Chem model captures many important features of the observations and gives confidence to using the model for understanding the spatio-temporal variability of ozone over South Asia. However, improvements of South Asian emission inventories and simulations at finer model resolution, especially over the complex Himalayan terrain in Northern India, are also essential for accurately simulating ozone in this region.
A multi-source satellite data approach for modelling Lake Turkana water level: calibration and validation using satellite altimetry data
Authors: Velpuri N. M. , Senay G. B. , Asante K. O.
Published: January 2012

Abstract. Lake Turkana is one of the largest desert lakes in the world and is characterized by high degrees of inter- and intra-annual fluctuations. The hydrology and water balance of this lake have not been well understood due to its remote location and unavailability of reliable ground truth datasets. Managing surface water resources is a great challenge in areas where in-situ data are either limited or unavailable. In this study, multi-source satellite-driven data such as satellite-based rainfall estimates, modelled runoff, evapotranspiration, and a digital elevation dataset were used to model Lake Turkana water levels from 1998 to 2009. Due to the unavailability of reliable lake level data, an approach is presented to calibrate and validate the water balance model of Lake Turkana using a composite lake level product of TOPEX/Poseidon, Jason-1, and ENVISAT satellite altimetry data. Model validation results showed that the satellite-driven water balance model can satisfactorily capture the patterns and seasonal variations of the Lake Turkana water level fluctuations with a Pearson's correlation coefficient of 0.90 and a Nash-Sutcliffe Coefficient of Efficiency (NSCE) of 0.80 during the validation period (2004–2009). Model error estimates were within 10% of the natural variability of the lake. Our analysis indicated that fluctuations in Lake Turkana water levels are mainly driven by lake inflows and over-the-lake evaporation. Over-the-lake rainfall contributes only up to 30% of lake evaporative demand. During the modelling time period, Lake Turkana showed seasonal variations of 1–2 m. The lake level fluctuated in the range up to 4 m between the years 1998–2009. This study demonstrated the usefulness of satellite altimetry data to calibrate and validate the satellite-driven hydrological model for Lake Turkana without using any in-situ data. Furthermore, for Lake Turkana, we identified and outlined opportunities and challenges of using a calibrated satellite-driven water balance model for (i) quantitative assessment of the impact of basin developmental activities on lake levels and for (ii) forecasting lake level changes and their impact on fisheries. From this study, we suggest that globally available satellite altimetry data provide a unique opportunity for calibration and validation of hydrologic models in ungauged basins.
Hydrologic and geochemical modeling of a karstic Mediterranean watershed
Authors: Nikolaidis N. P. , Bouraoui F. , Bidoglio G.
Published: January 2012

Abstract. The SWAT model was modified to simulate the hydrologic and chemical response of karstic systems and assess the impacts of land use management and climate change of an intensively managed Mediterranean watershed in Crete, Greece. A methodology was developed for the determination of the extended karst area contributing to the spring flow as well as the degree of dilution of nitrates due to permanent karst water volume. The modified SWAT model has been able to capture the temporal variability of both karst flow and surface runoff using high frequency monitoring data collected since 2004 in addition to long term flow time series collected since 1973. The overall hydrologic budget of the karst was estimated and its evaporative losses were calculated to be 28% suggesting a very high rate of karst infiltration. Nitrate chemistry of the karst was simulated by calibrating a dilution factor allowing for the estimation of the total karstic groundwater volume to approximately 500 million m3 of reserve water. The nitrate simulation results suggested a significant impact of livestock grazing on the karstic groundwater and on surface water quality. Finally, simulation results for a set of climate change scenarios suggested a 17% decrease in precipitation, 8% decrease in ET and 22% decrease in flow in 2030–2050 compared to 2010–2020. A validated tool for integrated water management of karst areas has been developed, providing policy makers an instrument for water management that could tackle the increasing water scarcity in the island.
Spatial patterns of North Atlantic Oscillation influence on mass balance variability of European Glaciers
Authors: Marzeion B. , Nesje A.
Published: January 2012

Abstract. We present and validate a set of minimal models of glacier mass balance variability. The most skillful model is then applied to reconstruct 7735 individual time series of mass balance variability for all glaciers in the European Alps and Scandinavia. Subsequently, we investigate the influence of atmospheric variability associated with the North Atlantic Oscillation (NAO) on the glaciers' mass balances. We find a spatial coherence in the glaciers' sensitivity to NAO forcing which is caused by regionally similar mechanisms relating the NAO forcing to the mass balance: In Southwestern Scandinavia, winter precipitation causes a correlation of mass balances with the NAO. In Northern Scandinavia, temperature anomalies outside the core winter season cause an anti-correlation between NAO and mass balances. In the Western Alps, both temperature and winter precipitation anomalies lead to a weak anti-correlation of mass balances with the NAO, while in the Eastern Alps, the influences of winter precipitation and temperature anomalies tend to cancel each other, and only on the southern side a slight anti-correlation of mass balances with the NAO prevails.
Teaching and Learning Classroom Action Research at a Distance in an Indonesian Urban Community
Authors: Sandra S.A. [None] , Andriani Durri , Antoro Sunu Dwi , Prayekti [None] , Warsito [None]
Published: January 2012

This action research project aims to understand whether teachers are mastering the knowledge and skills necessary to conduct classroom action research through two courses, Classroom Action Research (CAR) and Enhancing Teaching Professional Skills (PKP: Pemantapan Kemampuan Profesional), offered via distance education to Indonesian teachers and to identify areas for possible improvement of both courses. The research was conducted in two urban study centers located in the cities of Bogor and Tangerang in the Indonesian provinces of West Java and Banten. Data were collected via semi-structured interviews, classroom observations, questionnaires, and focus group discussions. All data were analyzed for patterns that might offer insight into the problems tutors and teacher-learners were facing as they worked through the Classroom Action Research (PTK: Penelitian Tindakan Kelas) module and tutorial. The research team from Indonesia Open University (UT: Universitas Terbuka) identified several problematic aspects of each course, including excessive lag time between the first and second courses, insufficient examples of model classroom action research projects, a lack of supervised practice of action research techniques, variability of tutorial quality, and a mismatch between course assessments and the content and purpose of the courses. While the findings of this study focus primarily on two distance courses offered by UT, they offer insight into the challenges of providing in-service teacher development via distance education in the Indonesian context. Key Words: Distance Learning, Classroom Action Research, Teacher Professional Skill
Teaching for Active Learning in Two Primary-Level Islamic Schools (Madrasahs) in North Sumatra
Authors: Suprayetno W. [None] , Nasution Irwan , Siahaan Amiruddin , Jaya Farida , Rafida Tien , Rakhmawati Fibri , Suharni [None]
Published: January 2012

Teaching for active learning is an instructional strategy that has been promoted for some time in Indonesia through various government educational reform initiatives and international development efforts. These efforts, however, have tended to target teachers in public primary schools (SD: sekolah dasar) or public junior high schools (SMP: sekolah menengah pertama) rather than equivalent schools in the Islamic education sector (madrasah ibtidâ’iyah and madrasah tsanawiyah). Utilizing data gathered from focus group discussions, individual interviews, and classroom discussions, this action research study examined the specific challenges faced by Islamic Studies teachers in teaching for active learning in two public Islamic primary schools (MIN: madrasah ibtidâ’iyah negeri) in the district of Deli Serdang, North Sumatra. Our article goes on to describe the difficulties Islamic Studies teachers have in applying active learning teaching strategies learned in demonstrations of teaching for active learning in science, mathematics and other secular subjects to Islamic Studies. Key Words: Islamic Education, Active Learning, Religious Studies, Indonesia
Active Learning and Student Engagement in Mathematics at Madrasah Ibtidâ’iyah Al-Jauharotunnaqiyah
Authors: Kartina Ir. , Samanhudi Udi , Aisyah Siti , Nulhakim Lukman , Evendi Sutrisno Sadji , Faturohman Maman
Published: January 2012

Teaching for active learning has been widely recognized as a more effective teaching methodology than traditional transmission models of teaching. However, numerous studies have documented the persistence of traditional teaching methods despite the extensive research literature on the effectiveness of teaching for active learning and frequent efforts to train teachers to use this approach in their classrooms. In this article a team of lecturers from the University of Sultan Ageng Tirtayasa (UNTIRTA: Universitas Sultan Ageng Tirtayasa) in Indonesia report on an action research project carried out at an elementary-level madrasah in the city of Cilegon. Members of the team gathered qualitative data through interviews, focus groups, and classroom observations in order to better understand the challenges teachers faced in teaching for active learning before designing and carrying out a collaborative intervention designed to help teachers use active learning strategies in a mathematics classroom. Key Words: Active Learning, Madrasah, Mathematics, Indonesia