bluuebunny/crossref_metadata_2025 huggingface dataset:
Hierarchical cluster analysis of yearling body weight and linear body measurementsof sheep of Northern Nigeria and their crosses
Authors: Iyiola-Tunji A. O.
Published: February 2021

This study was conducted at the Sheep Project Unit of Small Ruminant Research Programme (SRRP) of National Animal Production Research Institute (NAPRI), Ahmadu Bello University, Shika, Zaria. Balami, Uda and Yankasa breeds (sheep of Northern Nigeria) were crossed . A total of 65 Yankasa, 23 Uda and 16 Balami ewes were served by 4 Yankasa, 3 Uda and 3 Balami rams. The diallel breeding pattern produced 192 lambs. However, only the 65 yearling that survived up to 12 months of age (yearling) were used for this study. The yearling body weight and linear body measurement data were analysed using General Linear Model (GLM) procedures of SAS with model that incorporated lamb genotype as fixed effects. Pairwise difference was used to separate the mean (SAS, 2003). Distances were used to construct dendrogram using the Unweighted Pairs Group Method Analysis implemented in R 2.13.0 package. TREE procedure that prints the dendrogram based on the distances between the clusters was introduced in PROC CLUSTER procedure. Yearling genotype affected body weight and all the linear body measurements considered in this study (P<0.05). The pure Balami yearling (BL X BL) had the highest birth weight at 12 months of age (29.10±4.02kg). Clumping structure of yearling body weight among sheep of Northern Nigeria and their crosses were grouped into two clusters at distance 2.656. Pure Balami (BL X BL) formed the first cluster while the rest of the genotypes belong to the second cluster. The second cluster was further divided into two sub-groups at 0.796. The first sub-group had yearlings from pure Uda (UD X UD), Uda ram and Yankasa ewe (UD X YK), Uda ram and Balami ewe (UD X BL), Balami ram and Uda ewe (BL X UD) and Yankasa ram and Uda ewe (YK X UD) at 0.514. Similar clumping structures with two clusters share among the nine genotypes at varied distances were recorded for all the linear body measurements studied. Patterns of similarities were established for yearling body weight and linear body measurements among sheep of Northern Nigeria and their crosses. Improvement plans for yearling growth traits of sheep in Nigeria should consider the genotypes with divergent genetic distances as sires and dams. This will ensure the best exploration of positive heterosis.
Genetic variability of Nigerian sheep breeds at the insulin-like growth factor-1 (IGF-1) gene locus
Authors: Mohammed A. , Raji A. O. , Igwebuike J. U.
Published: February 2021

The genetic variability of some Nigerian breeds of sheep at the IGF 1 locus was investigate blood samples from 150 sheep (50 each of Yankasa, Balami and Uda sheep) were collected from the Maiduguri abbatoir and analysed at the Biotechnology centre of the University of Maiduguri. A relatively high level of genetic variability was detected in Nigerian sheep; the mean observed heterozygosity (Ho) and expected heterozygosity (He) values were 0.433 and 0.476, respectively. Comparison of expected heterozygosity of alleles between the populations showed that yankasa was the most heterozygous of the sheep populations though the unbiased expected heterozygosity (0.503) for the Yankasa was the same as that of the Balami. All populations were 100% polymorphic at the IGF 1 locus with fixation index ranging from -0.169 to 0.378 and a mean of 0.093, which suggests a general pattern of random mating. Similarly, low mean values for Fis (0.093), F (0.089), Fis (0.089), Fit (0.130) and Fst (0.045) supports the assertion that inbreeding was limited due to outcrossing with relatively high level of gene-flow (Nm = 5.292). The analysis of molecular variance (AMOVA) revealed that only 1% of the total variations observed in the sampled populations is accounted for by the population differences while individual differences accounted for 85%. The UPGMA phylogenetic tree revealed that the Uda and Yankasa populations are closer to each than each is to Balami. Thus, it can be concluded that sufficient genetic variation exist in the studied Nigerian sheep breeds and these populations are unlikely to decline due to inbreeding.
Nutrient digestibility and blood parameters of West African dwarf sheep fed sugarcane top silage
Authors: Adelusi O. O. , Ojo V. O. A.
Published: February 2021

Nutritive value of low quality crop residues is improved with addition of protein–rich byproducts (poultry litter) or chemical compounds (urea) and can serve as feed resource to ruminant during the dry season. This study investigated the nutrient digestibility and blood parameters of West African dwarf (WAD) sheep fed sugarcane top silage. Sugarcane tops were ensiled alone (control) or with 2% urea (USCT silage), 45% boiler litter (BLSCT silage) and 1% urea plus 22.5% broiler litter (UBLSCT) for 42 days. Each silage treatment contains 2% molasses. Twenty-four female West African dwarf sheep of 6-8 months of age, weighing 14.58±1.16kg were randomly assigned to the four silage treatments of six animals each in a completely randomised design for 84 days. Chemical composition of the silages was determined. Performance characteristics, apparent nutrient digestibility and blood parameters of the WAD sheep were evaluated. All data were subjected to one way Analysis of Variance. Results showed that animals fed BLSCT had significantly highest (P<0.05) total dry matter intake (64.26g/kgW ) and daily weight gain (46.03 g/day) followed by those on UBLSCT and USCT while animals fed control diet recorded the least with highest feed conversion ratio (20.62). Digestibility of all nutrients was highest (P<0.05) in sheep fed BLSCT (71.43%,71.16%, 75.66%, 64.35% and 56.82% for dry matter, organic matter, crude protein, NDF and ADF digestibility respectively) and lowest (55.71%, 57.31%, 59.98%, 39.47% and 46.92% for dry matter, organic matter, crude protein, NDF andADF digestibility respectively ) in those on control diet. Similarly, sheep fed BLSCT recorded significant highest (P < 0.05) packed cell volume (32.17%), haemoglobin (10.82g/dL) and red blood cell (13.43 x10 /L). The serum glucose, total protein, albumin, globulin and blood urea concentration were similar (P > 0.05) but higher in animals fed BLSCT (3.94 mmol/L, 71.80 g/L, 37.00 g/L, 34.80 g/L and 130.55 mg/L, respectively) USCT(3.83 mmol/L, 71.50 g/L, 35.0 g/L, 36.50 g/L and 140.65 mg/L respectively) and UBLSCT (3.75 mmol/L, 71.20 g/L, 34.50g/L, 36.70 g/L and 120.90 mg/L, respectively) compared to control. The study concluded that SCTtreated with urea or broiler litter or their combination (UBLSCT) ensiled for 42 days could be fed to ruminant during long dry season without any detrimental effect onnthe health of the animals.
Comparative evaluation of hydroponic maize fodder and conventional basal diet on performance, digestibility and blood profile of weaned pigs
Authors: Adebiyi O. A. , Adefila T. A. , Adeshola A.T.
Published: February 2021

High cost of conventional feedstuffs has resulted to the need to exploit the diverse feed resources for improved sustainability in swine production. Hydroponic sprouts which undergo nutritional modification during the sprouting process are a good source of nutrients that could improve the performance of pigs. Hence, nutrient digestibility, performance, haematological and serum biochemical parameters of weaned pigs fed hydroponic maize fodder (HMF) and conventional basal based diets were studied. Thirty-six (36) crossbred weaned pigs were randomly allotted to three treatments with four replicates each in a completely randomized design. Treatment 1 (T1) had 50% hydroponically grown maize sprouts + 50% concentrate, Treatment 2 (T2) had 100% hydroponically grown maize sprouts and Treatment 3 (T3) had 100% basal diet (cassava peel +palm kernel cake +brewery dried grain). The experiment lasted 6 weeks. Significant differences (P<0.05) were observed in the apparent digestibility of nutrients, performance and blood profile of pigs across dietary treatments. T1 had higher (P<0.05) apparent crude protein digestibility (65.76%) while the lowest (55.27%) was observed in T2 with a similar trend observed for apparent crude fibre digestibility. Apparent ether extract digestibility was higher (P<0.05) in T2 (68.43%) and lowest in T3 (65.47%) while ash digestibility was (P<0.05) highest in T3 (46.08%). Significantly higher values were obtained in T3 for final weight (13.83kg), feed intake (12.79kg) and weight gain (3.83kg) while least values were observed in T2. However, T1 had the highest value for FCR (3.68kg) while comparable values were obtained for feed cost/weight gain in pigs fed T1 and T3. T1 had higher (p<0.05) RBC (5.73×10 µl), WBC (1.80×10 µl), lymphocytes (69%) and eosinophils (3.67%) values while lowest values were obtained in T2 for PCV (34.67%), RBC (5.08×10 µl) and lymphocytes (56.33%). Significant differences (P<0.05) were also observed for cholesterol, triglycerides, LDL, VLDL, total protein, globulin and albumin while glucose and HDL showed no differences (P>0.05). All values obtained for haematology and serum biochemical parameters were within the normal physiological range of the animals.In conclusion, hydroponics maize fodder when combined with concentrate feed had a positive impact on nutrient digestibility and performance of pigs. Also, haematological and serum biochemical indices of pigs were not negatively affected.
Carcass traits, haematology and serum biochemical parameters of Nigerian indigenous chickens and their crosses with marshall
Authors: Akpan U. , Bassey O. A. , Ikeobi C.O.N. , Jegede A.V. , Adebambo O.A.
Published: February 2021

This study investigated the genetic variation in carcass traits and blood parameters of local naked neck and normal-feathered chickens and their crosses with Marshall broiler chickens. Two hundred and sixty three chickens consisting of 50 purebred Marshalls (M), 38 naked neck (Nk) and 48 normal-feathered (N), 61Marshall x naked neck (MNk) and 66Marshall x normal-feathered(MN) chickens were used for the study. Data were collected on carcass traits, haematology and serum biochemical parameters and were analysed using the General Linear Model procedure of Statistical Analysis System. Carcass traits such as eviscerated weight and weights of thigh, drumstick, breast, wings and organs were significantly (P < 0.0001) affected by genotype. Results showed that the purebred Marshall had the highest values in most of the traits followed by their crossbreds. In organs such as gizzard, liver and heart the local normal feathered ranked equal with its crossbred. Sex significantly (P< 0.05) affected carcass traits. Males consistently had higher values than females in all the parameters measured. Genotype significantly (P
Effects of credit rationing on the returns of poultry farmers in Ogun State, Nigeria
Authors: Yusuf W. A. , Agbontafara R. O. , Yusuf S. A.
Published: February 2021

In Nigeria, agricultural credit has long been identified as a major input in the development of the agricultural sector. Thus, the study was carried out in order to examine the effects of credit rationing on the returns of poultry farmers in Ogun state, Nigeria. In the study, primary data obtained from 120 farmers through the use of questionnaires were used. The data were analysed using descriptive statistics, multinomial logit model and gross margin analysis. The result revealed that 59.22% of the sampled farmers obtained their capital from personal savings while 18.45% and 14.56% of them sourced theirs from cooperative organisations and banks, respectively. The study also affirmed that many of the farmers who source for credit outside their personal savings preferred getting credit from cooperative associations/savings associations because the source was less collateral-demanding, charges relatively lower interest rates, required bearable procedures and conditions for borrowing credit. The multinomial logit analysis showed that interest rate was significant at 5%level under cooperative/savings association sources. This implied that interest rate was a determining factor for sourcing credit from cooperative associations. The regression result also showed that interest rate on credit and distance of the farm households from credit source, contributed negatively, while gender and collateral contributed positively to the returns of poultry farmers. The result of the gross margin analysis showed that the total variable cost incurred by the farmers increased as the amount of credit/loan received increased. Hence, the informal finance providers were the backbone of small scale farmers. It is therefore recommended that the bureaucratic procedures for obtaining credit, from formal sources, should bemade flexible enough to accommodate small scale farmers.
Growth indices, haematological parameters, carcass attributes and economics of production of rabbits fed graded levels of kolanut testa
Authors: Balogun K. B. , Sokunbi O. A. , Ayoola M. A.
Published: February 2021

The cost of feed is the main cause of high cost of production of rabbits. Kolanut testa, a protective covering of the kolanut seed (Cola nitida) is readily available as by-product in areas where kolanut is produced. Thus, the objective of this study was to assess the growth performance, carcass attributes, haematological parameters and economics of production of rabbits fed diets with varying inclusions levels of kolanut testa (KOT) as replacement for maize. Thirty mixed breed rabbits of mixed sexes were used for this experiment. The rabbits were randomly allotted into 5 treatment groups. Five experimental diets were formulated such that KOT replaced maize at 0, 10, 20, 30 and 40%. Records of feed intake and weight gain were properly taken and blood samples were collected and analysed for their haematological parameters at the end of the experiment. Cost analysis using dedicated formulae was done to determine economics of production. The experiment lasted for eight weeks. Data were analyzed using Analysis of Variance. No significant (P>0.05) difference was recorded in all the parameters measured to determine growth performance. The same applies to parameters measured for carcass attributes except for weight of limbs. Significant (P<0.05) difference was however recorded among mean values of PCV (28.67-36.33%), 6 3 3 3RBC (3.14-4.12x10/mm), WBC (3.10-5.87x10/mm) and Mon (1.40-1.67%) of the experimental animals. Cost of feed decreased with increase in KOT inclusion (N139.8N112.54). Cost of feed (N/kg) weight gain (N1023.61-N583.04); cost of weight gain (N573.22-N483.92); and total cost (N2143.61-N1523.92) all followed similar pattern. Cost differential (205.93–440.04) and relative cost benefit (20.11–43.04%) increased with increase in the level of replacement of KOT. Conclusively, growth performance was not negatively affected and total weight gain was numerically highest at 40% (916.67g) with no deleterious effect on the health of the rabbits. Also, the highest relative cost benefit was recorded at 40% (28.54%). These prove that KOT is a viable substitute for maize in rabbit diet and it is more economical at 40% replacement level.
Effects of cassava meal on carcass characteristics and cholesterol of growing pig
Authors: Adeyemi M. A. , Akinfala E. O.
Published: February 2021

Twenty growing pigs with an average initial weight of 20.00 + 0.5 kg were randomly assigned to five dietary treatments in a completely randomized design with two replicates per treatment and two animals in each replicate. Cassava Plant Meal (CPM) prepared from sundried unpeeled cassava tubers, leaves and tender cassava stems, mixed at ratio 3:1 of unpeeled tuber meal to cassava leaf meal plus tender stem meal with the ratio of cassava leaf meal to tender stem meal as 5:1 was included in balanced rations at graded levels of 0, 25, 50, 75 and 100 percent in a fifty-six days feeding trials. The experimental pigs were weighed before and after slaughtering, dressing percent was evaluated and carcass length and back fat depth were measured on treatment basis. Meat samples were collected at the ribs (2nd and v3rd and also 12th and 13th) for cholesterol analysis. The 50 % CPM diet produced the heaviest slaughter weight. There was no significant (p >0.05) difference in the dressing percentage of pigs across dietary treatments although pigs on the control diet dressed well while pigs on 100 % CPM dressed the poorest. The 100 % CPM diet induced the leanest carcass. All the carcass and organ measurements were significantly (p <0.05) affected by dietary treatments. There was non-significant (p >0.05) influence of dietary treatments on total and high density lipoprotein cholesterol although the 50 % CPM diet produced the least and highest values respectively. Low density and very low density lipoprotein cholesterol were significantly (p <0.05) affected by dietary treatments. Replacement of maize by varying levels of cassava plant meal diets enhanced production of leaner carcass.
Preliminary in vitro screening of some spices and medicinal plants from Edo and Rivers States, Nigeria for reducing enteric methane production in ruminants
Authors: Bamikole M. A. , Babayemi O. J. , Lamidi A. A. , Ayinde B. A. , Ikhatua U. J. , Ojeaga S. , Ezemba T. , Alaita O.
Published: February 2021

Methane gas produced by ruminants during feed fermentation contributed to global warming as well as poor efficiency of food utilization. Mitigating ruminal methane production through anti-microbial feed additive has serious health implications. A preliminary study of the potential of medicinal plants and spices from Edo and Rivers State, as possible replacement to antibiotic feed additives was carried out. Medicinal plants and spices were purposefully sampled, dried at 40oC, milled and 10 mg was added with 190 mg of substrate in a preweighed nylon incubation bags. Bags and their contents were incubated using 30 mL of buffered rumen liquor in 100 mL syringes following the standard procedure of in vitro fermentation. Variables monitored were 24h total gas volume, short chain fatty acids (SCFA) methane (CH4 ) gas, dry matter degradability (DMD) as well as some chemical, cell wall and anti-nutritive components. Results revealed that adding the medicinal plants and spices as feed additives did not depress gas production in most cases (19.5 – 29.50 mL, 17.75 – 30.00 mL and 12.00 – 29.00 mL for Edo medicinal plants, Edo spices and Rivers medicinal plants respectively) and also did not depress DMD (> 50%). Azadirachta indica stem reduced CH4 production mostly by 53.56% while Dennttia tripetala did by 47.69% among the Edo medicinal plants and spices, respectively. In Rivers State, Amaranthus spinosus gave the highest value of 60.33% CH4 reduction. In the same bracket of similar and good CH4 reduction potentials were Alstonia boonei leaves (49.06%), Newbouldia laevis root (41.50%), Euphorbia heterophyla (37.97%), Allium crispum (47.31%), Allium cepa (46.80%), Aframomum mueguata (46.54%), Capsicum annum (47.32%), Ageratum conyzoides (56.52%), Lagenaria breviflora (48.03%) and Centrosema molle (45.08%). All the medicinal plant and spices with potential for CH4 reduction had corresponding high SCFA values (0.46 – 0.65 Mmol) with tannin (%) and saponin (%) contents of 0.011 – 17.50 and 0.01 – 2.40 respectively. Conclusively, the medicinal plants and spices demonstrated good potentials for reducing rumen methane production in vitro and may be subjected to further in vivo studies.
Effect of genotype on semen quality traits of main and reciprocal crossbred chickens
Authors: Isaac U. C. , Udoh U. H. , Nosike R. J.
Published: February 2021

Semen quality of cocks is of utmost importance in reproduction. Breeding method, breed, strain and genetic constitution are the major components of the genetic factors capable of affecting the semen quality of cocks. This research seeks to determine the effect of genotype on the semen quality traits of 272 F crossbred cocks produced at day-old by main and 1 reciprocal crossbreeding of 69 Isa Brown and local frizzle feathered, naked neck and normal feathered chickens. The genotypes of the cocks were Isa Brow x frizzle feathered main cross (IBxF), Isa Brown x naked neck main cross (IBxNa), Isa Brown x normal feathered main cross (IBxN), frizzle feathered x Isa Brown reciprocal cross (FxIB), naked neck x Isa Brown reciprocal cross (NaxIB) and normal feathered x Isa Brown reciprocal cross (NxIB). At 36-40 weeks of age, semen was extracted from the cocks by abdominal  massage technique and used to evaluate semen volume (SV), sperm motility (SM), sperm concentration (SC) and live sperm (LS) at weekly intervals. Data obtained from the evaluation were subjected to analysisof variance and tested at 5% level of probability. Genotypes differed significantly (P <0.05) in SC at 37-40 weeks and in SM and LS at all ages. There was no significant difference (P>0.05) in SV. Regardless of genotype and age, the mean SV, SM, SC and LS ranged from 0.31±0.02 to 0.24±0.01ml, 71.84±1.33 to 58.75±2.16 %, 3.22±0.02 to2.92±0.02 x109/ml and 71.91±1.37 %, respectively. The NxIB and IBxNa genotypes produced largest numericalsemen volume at 37 and 39 weeks of age respectively. Whereas SC and LS were significantly highest for IBxF and IBxN respectively at week 37, SM was so for IBxN at all ages. Further, the LS of IBxN genotype was significantly highest at 36-38 and 40 weeks of age. The exotic Isa Brown and normal feathered main cross cocks exhibited the best semen quality traits among all genotypes studied and should be selected for improvement of the reproductive characteristics of cocks.
Organoleptic evaluation of Archachatina marginata fed rumen content dietary inclusion
Authors: Raimi C. O. , Odeyemi A. C.
Published: February 2021

There is inadequate information on quality feedstuff for large scale production and all year round availability of snails in Nigeria.The research was conducted to investigate the organoleptic properties of the African giant land snails (Archachatina marginata). Thirtytwo snails were randomly allotted into four dietary treatments of varied levels of 0%, 5%, 10% and 15% rumen content inclusion. Each treatment was replicated with four snails per pen in a completely randomized design. The snails were reared in mini paddock. Feed and water were supplied ad-libitum. At the end of the eight weeks period of feeding trials, two snails were harvested at random from the replicates of each of the four treatments, sacrificed, processed and analyzed. Based on appearance, taste and aroma of the snails fried and stewed with spices and the other one steamed with spices, preference ranking in descending order revealed 15% (6·85) rumen content inclusion had the highest mean preference followed by 5% (6·53) inclusion for the fried snail with spices and 0% (6.65) inclusion had the highest ranking followed by 15% (6.53) rumen content inclusion for the snail steamed with spices. The treatments had no appreciable effect on the nutrient composition and sensory quality of the snail meat. It can be concluded that growing snails can utilize rumen content inclusion thereby increasing the feed data base for snail production in the Tropics.
Growth performance and haematological profile of broiler chickens served dietary inclusion of probiotics (Saccharomyces cereviasae) and enzyme (bio-enzyme)
Authors: Udeh F. U. , Ilo S. U. , Udeh V. C.
Published: February 2021

This study was conducted to evaluate the growth performance and haematological profiles of broiler chickens served dietary inclusion of probiotics (Saccharomyces cereviasae) and enzyme (Bio-enzyme). One hundred and twenty, one day-old broiler chicks of Agrited strain were used for the study. The birds were randomly allotted to four dietary treatments. Each treatment contained 30 birds replicated three times to contain 10 birds per replicate in a completely randomized design experiment. The four dietary treatments were T1 Control (no probiotics and enzyme), T2 (had both probiotics and enzyme), T3 (probiotics only) and T4 (Enzyme only). The birds were given feed and water ad-libitum and the quantity of feed consumed each day was determined through weigh back techniques while the birds were weighed weekly throughout the experimental period. The experiment lasted eight weeks. The results showed significant (p<0.05) differences in the final body weight, total weight gain, average daily weight gain, total feed intake, average daily feed intake and feed conversion ratio. Chickens on treatment 2 had the highest final body weight of 3011.57g and performed better than chickens in other dietary treatments. Similar trend was observed in the haematological profile as treatment two were highest in value across the treatments and parameters measured except in packed cell volume where the highest value (36.33 %) was recorded in treatment 4. It was concluded from the study that treatment two which contained both probiotics and enzyme performed better and thus, recommended to farmers for broiler production.
PENGARUH MODEL BRAIN BASED LEARNING TERHADAP HASIL BELAJAR SISWA
Authors: Syarifudin Achmad , Dhewy Risdiana Chandra , Agustina Eka Nurmala Sari
Published: February 2021

Untuk melihat peningkatan siswa dalam proses pembelajaran, salah satunya adalah  nilai hasil belajar. Supaya membuat siswa berperan aktif dalam proses pembelajaran materi segi empat bangun trapesium di kelas, maka dapat menerapkan model Brain Based Learning dimana siswa diminta aktif untuk menggali pengetahuan agar dapat meningkatkan hasil belajar. Penelitian ini bertujuan untuk mengetahui adanya pengaruh model Brain Based Learning terhadap hasil belajar siswa pada materi segi empat. Penelitian ini adalah eksperimen dengan menggunakan pendekatan kuantitatif, yang dilaksanakan pada tahun ajaran 2020/2021 di SMP Kemala Bhayangkari 7 Porong dengan sampel 29 siswa pada kelas VII-A. Hasil penelitian ini menyatakan bahwa hasil belajar siswa pada materi segi empat bangun trapesium yang dilihat  dari nilai thitung = 2,797 > ttabel = 2,051 dengan kondisi probabilitas signifikan (0,009) kurang dari α (0,05). Selain itu ditunjukkan juga dengan persamaan regresi linear yaitu -253,494+3,808X yang memperlihatkan bahwa jika model Brain Based Learning dilaksanakan semakin baik dengan persiapan yang matang sehingga hasil belajar siswa meningkat dengan baik. Model Brain Based Learning memiliki kontribusi/pengaruh sebesar 22,5 % pada proses pembelajaran materi segi empat .
Revisiting the reaction of dicarbonyls in aerosol proxy solutions
containing ammonia: the case of butenedial
Authors: Hensley Jack C. , Birdsall Adam W. , Valtierra Gregory , Cox Joshua L. , Keutsch Frank N.
Published: February 2021

Abstract. Reactions in aqueous solutions containing dicarbonyls (especially the α-dicarbonyls methylglyoxal, glyoxal, and biacetyl) and reduced nitrogen (NHx) have been studied extensively. It has been proposed that accretion reactions from dicarbonyls and NHx could be a source of particulate matter and brown carbon in the atmosphere and therefore have direct implications for human health and climate. Other dicarbonyls, such as the 1,4-unsaturated dialdehyde butenedial, are also produced from the atmospheric oxidation of volatile organic compounds, especially aromatics and furans, but their aqueous phase reactions with NHx have not been characterized. In this work, we determine a pH-dependent mechanism of butenedial reactions in aqueous solutions with NHx that is compared to α-dicarbonyls, in particular the dialdehyde glyoxal. Similar to glyoxal, butenedial is strongly hydrated in aqueous solutions. Butenedial reaction with NHx also produces nitrogen-containing rings and leads to accretion reactions that form brown carbon. Despite glyoxal and butenedial both being dialdehydes, butenedial is observed to have three significant differences in its chemical behavior: (1) as previously shown, butenedial does not substantially form acetal oligomers, (2) the butenedial/OH− reaction leads to light-absorbing compounds, and (3) the butenedial/NHx reaction is fast and first order in the dialdehyde. Building off of a complementary study on butenedial gas-particle partitioning, we suggest that the behavior of other reactive dialdehydes and dicarbonyls may not always be adequately predicted by α-dicarbonyls, even though their dominant functionalities are closely related. The carbon skeleton (e.g., its hydrophobicity, length, and bond structure) also governs the fate and climate-relevant properties of dicarbonyls in the atmosphere. If other dicarbonyls behave like butenedial, their reaction with NHx could constitute a regional source of brown carbon to the atmosphere.
Technical note: First comparison of wind observations from ESA's satellite mission Aeolus and ground-based radar wind profiler network of China
Authors: Guo Jianping , Liu Boming , Gong Wei , Shi Lijuan , Zhang Yong , Ma Yingying , Zhang Jian , Chen Tianmeng , Bai Kaixu , Stoffelen Ad , de Leeuw Gerrit , Xu Xiaofeng
Published: February 2021

Abstract. Aeolus is the first satellite mission to directly observe
wind profile information on a global scale. After implementing a set of bias
corrections, the Aeolus data products went public on 12 May 2020. However,
Aeolus wind products over China have thus far not been evaluated extensively by
ground-based remote sensing measurements. In this study, the Mie-cloudy and
Rayleigh-clear wind products from Aeolus measurements are validated against
wind observations from the radar wind profiler (RWP) network in China. Based
on the position of each RWP site relative to the closest Aeolus ground
tracks, three matchup categories are proposed, and comparisons between Aeolus
wind products and RWP wind observations are performed for each category
separately. The performance of Mie-cloudy wind products does not change much
between the three matchup categories. On the other hand, for Rayleigh-clear
and RWP wind products, categories 1 and 2 are found to have much smaller
differences compared with category 3. This could be due to the RWP site
being sufficiently approximate to the Aeolus ground track for categories 1 and
2. In the vertical, the Aeolus wind products are similar to the RWP wind
observations, except for the Rayleigh-clear winds in the height range of
0–1 km. The mean absolute normalized differences between the
Mie-cloudy (Rayleigh-clear) and the RWP wind components are 3.06 (5.45),
2.79 (4.81), and 3.32 (5.72) m/s at all orbit times and ascending and
descending Aeolus orbit times, respectively. This indicates that the wind
products for ascending orbits are slightly superior to those for descending
orbits, and the observation time has a minor effect on the comparison. From
the perspective of spatial differences, the Aeolus Mie-cloudy winds are
consistent with RWP winds in most of east China, except in coastal areas
where the Aeolus Rayleigh-clear winds are more reliable. Overall, the
correlation coefficient R between the Mie-cloudy (Rayleigh-clear) wind and RWP
wind component observation is 0.94 (0.81), suggesting that Aeolus wind
products are in good agreement with wind observations from the RWP network
in China. The findings give us sufficient confidence in assimilating the
newly released Aeolus wind products in operational weather forecasting in
China.
Airborne extractive electrospray mass spectrometry measurements of the chemical composition of organic aerosol
Authors: Pagonis Demetrios , Campuzano-Jost Pedro , Guo Hongyu , Day Douglas A. , Schueneman Melinda K. , Brown Wyatt L. , Nault Benjamin A. , Stark Harald , Siemens Kyla , Laskin Alex , Piel Felix , Tomsche Laura , Wisthaler Armin , Coggon Matthew M. , Gkatzelis Georgios I. , Halliday Hannah S. , Krechmer Jordan E. , Moore Richard H. , Thomson David S. , Warneke Carsten , Wiggins Elizabeth B. , Jimenez Jose L.
Published: February 2021

Abstract. We deployed an extractive electrospray ionization
time-of-flight mass spectrometer (EESI-MS) for airborne measurements of
biomass burning aerosol during the Fire Influence on Regional to Global
Environments and Air Quality (FIREX-AQ) study onboard the NASA DC-8 research
aircraft. Through optimization of the electrospray working solution, active
control of the electrospray region pressure, and precise control of
electrospray capillary position, we achieved 1 Hz quantitative measurements
of aerosol nitrocatechol and levoglucosan concentrations up to pressure
altitudes of 7 km. The EESI-MS response to levoglucosan and nitrocatechol was
calibrated for each flight, with flight-to-flight calibration variability of
60 % (1σ). Laboratory measurements showed no aerosol size
dependence in EESI-MS sensitivity below particle geometric diameters of 400 nm, covering 82 % of accumulation-mode aerosol mass during FIREX-AQ. We
also present a first in-field intercomparison of EESI-MS with a chemical
analysis of aerosol online proton-transfer-reaction mass spectrometer
(CHARON PTR-MS) and a high-resolution Aerodyne aerosol mass spectrometer
(AMS). EESI-MS and CHARON PTR-MS levoglucosan concentrations were well
correlated, with a regression slope of 0.94 (R2=0.77). AMS
levoglucosan-equivalent concentrations and EESI-MS levoglucosan showed
a greater difference, with a regression slope of 1.36 (R2=0.96),
likely indicating the contribution of other compounds to the AMS
levoglucosan-equivalent measurement. The total EESI-MS signal showed correlation
(R2=0.9) with total organic aerosol measured by AMS, and the
EESI-MS bulk organic aerosol sensitivity was 60 % of the sensitivity to
levoglucosan standards.
Eddy permitting simulations of freshwater injection from major
Northern Hemisphere outlets during the last deglacial
Authors: Love Ryan , Andres Heather , Condron Alan , Tarasov Lev
Published: February 2021

Abstract. Freshwater, in the form of glacial runoff, is hypothesized to play a critical role in centennial to millennial scale climate variability such as the Younger Dryas and Dansgaard-Oeschger Events. Indeed, freshwater injection/hosing experiments with climate models have long shown that freshwater has the capability of generating such abrupt climate transitions. However, the relationship between freshwater and abrupt climate transitions is not straightforward. Large-scale glacial runoff events, such as Meltwater Pulse 1A, are not always temporally proximal to subsequent large-scale cooling. As well, the typical design of hosing experiments tends to artificially amplify the climate response. This study explores the impact that limitations in the representation of runoff in conventional hosing simulations has on our understanding of this relationship and addresses the more fundamental question of where coastally released freshwater is transported when it reaches the ocean. We focus particularly on the prior use of excessive freshwater volumes (often by a factor of 5) and present-day (rather than paleo) ocean gateways, as well as the injection of freshwater directly over sites of deep-water formation (DWF) rather than at runoff locations. We track the routing of glaciologically-constrained freshwater volumes from four different plausible injection locations in a suite of eddy-permitting glacial ocean simulations using MITGCM under both open and closed Bering Strait conditions. Restricting freshwater forcing values to realistic ranges results in less spreading of freshwater across the North Atlantic and indicates that the response of DWF depends strongly on the geographical location of meltwater input. In particular, freshwater released into the Gulf of Mexico has little impact on DWF regions as a result of turbulent mixing by the Gulf Stream. In contrast, freshwater released from the Eurasian Ice sheet or initially into the Arctic is found to have the largest impact on DWF in the North Atlantic and GIN seas. Additional experiments show that when the Bering Strait is open, much like present-day, the Mackenzie River source exhibits twice as much freshening of the Labrador sea as a closed Bering Strait. Finally, our results illustrate that applying a freshwater hosing directly into the North Atlantic with even realistic freshwater amounts still over-estimates the effect of terrestrial runoff on ocean circulation.
Mid-Pliocene West African Monsoon Rainfall as simulated in the
PlioMIP2 ensemble
Authors: Berntell Ellen , Zhang Qiong , Li Qiang , Haywood Alan M. , Tindall Julia C. , Hunter Stephen J. , Zhang Zhongshi , Li Xiangyu , Guo Chuncheng , Nisancioglu Kerim H. , Stepanek Christian , Lohmann Gerrit , Sohl Linda E. , Chandler Mark A. , Tan Ning , Contoux Camille , Ramstein Gilles , Baatsen Michiel L. J. , von der Heydt Anna S. , Chandan Deepak , Peltier William Richard , Abe-Ouchi Ayako , Chan Wing-Le , Kamae Youichi , Williams Charles J. R. , Lunt Dan
Published: February 2021

Abstract. The mid-Pliocene Warm Period (mPWP; ~3.2 million years ago) is seen as the most recent time period characterized by a warm climate state, with similar modern geography and ~400 ppmv atmospheric CO2 concentration, and is therefore often considered an interesting analogue for near-future climate projections. Paleoenvironmental reconstructions indicate higher surface temperatures, decreasing tropical deserts, and a more humid climate in West Africa characterized by a strengthened West African Monsoon (WAM). Using model results from the second phase of the Pliocene Modelling Intercomparison Project (PlioMIP2) ensemble we analyze changes of the WAM rainfall during the mPWP, by comparing with the control simulations for the pre-industrial period. The ensemble shows a robust increase of the summer rainfall over West Africa and the Sahara region with an average increase of 2.7 mm/day, contrasted by a rainfall decrease over the equatorial Atlantic. An anomalous warming of the Sahara Desert and deepening of the Saharan Heat Low, seen in > 90 % of the models, leads to a strengthening of the WAM and an increased monsoonal flow into the continent. A similar warming of the Sahara Desert is seen in future projections using both phase 3 and 5 of the Coupled Model Intercomparison Project (CMIP3 and CMIP5), and though previous studies of future projections indicate a west/east drying/wetting contrast over Sahel, PlioMIP2 simulations indicate a uniform rainfall increase over Sahel in warm climates characterized by increasing greenhouse gas forcing.
A novel hydrographic gridded data set for the northern Antarctic Peninsula
Authors: Dotto Tiago S. , Mata Mauricio M. , Kerr Rodrigo , Garcia Carlos A. E.
Published: February 2021

Abstract. The northern Antarctic Peninsula (NAP) is a highly
dynamic transitional zone between the subpolar-polar and oceanic-coastal
environments, and it is located in an area affected by intense climate
change, including intensification and spatial shifts of the westerlies as
well as atmospheric and oceanic warming. In the NAP area, the water masses
originate mainly from the Bellingshausen and Weddell seas, which create a
marked regional dichotomy thermohaline characteristic. Although the NAP area
has relatively easy access when compared to other Southern Ocean
environments, our understanding of the water masses' distribution and the
dynamical processes affecting the variability of the region is still
limited. That limitation is closely linked to the sparse data coverage, as is
commonly the case in most Southern Ocean environments. This work
provides a novel seasonal three-dimensional high-resolution hydrographic
gridded data set for the NAP (version 1), namely the NAPv1.0. Hydrographic
measurements from 1990 to 2019 comprising data collected by conductivity,
temperature, depth (CTD) casts; sensors from the Marine Mammals
Exploring the Oceans Pole to Pole (MEOP) consortium; and Argo floats have been optimally
interpolated to produce maps of in situ temperature, practical salinity, and
dissolved oxygen at ∼ 10 km spatial resolution and 90 depth
levels. The water masses and oceanographic features in this regional gridded
product are more accurate than other climatologies and state estimate
products currently available. The data sets are available in netCDF format
at https://doi.org/10.5281/zenodo.4420006 (Dotto et al., 2021). The novel
and comprehensive data sets presented here for the NAPv1.0 product are a
valuable tool to be used in studies addressing climatological changes in the
unique NAP region since they provide accurate initial conditions for ocean
models and improve the end of the 20th- and early 21st-century ocean
mean-state representation for that area.
Real-time WRF large-eddy simulations to support uncrewed aircraft system (UAS) flight planning and operations during 2018 LAPSE-RATE
Authors: Pinto James O. , Jensen Anders A. , Jiménez Pedro A. , Hertneky Tracy , Muñoz-Esparza Domingo , Dumont Arnaud , Steiner Matthias
Published: February 2021

Abstract. The simulation dataset described herein provides a high-resolution depiction
of the four-dimensional variability of weather conditions across the
northern half of the San Luis Valley, Colorado, during the 14–20 July 2018
Lower Atmospheric Profiling Studies at Elevation-A Remotely-Piloted
Aircraft Team Experiment (LAPSE-RATE) field program. The simulations
explicitly resolved phenomena (e.g., wind shift boundaries, vertical shear,
strong thermals, turbulence in the boundary layer, fog, low ceilings
and thunderstorms) that are potentially hazardous to small uncrewed aircraft system (UAS) operations.
Details of the model configuration used to perform the simulations and the
data-processing steps used to produce the final grids of state variables and
other sensible weather products (e.g., ceiling and visibility, turbulence)
are given. A nested (WRF) model configuration was used in which the
innermost domain featured large-eddy-permitting 111 m grid spacing. The
simulations, which were executed twice per day, were completed in under 6 h on the National Center for Atmospheric Research (NCAR) Cheyenne
supercomputer using 59 cores (2124 processors). A few examples are provided
to illustrate model skill at predicting fine-scale boundary layer structures
and turbulence associated with drainage winds, up-valley flows and
convective storm outflows. A subset of the data is available at the Zenodo
data archive (https://zenodo.org/record/3706365#.X8VwZrd7mpo, Pinto
et al., 2020b) while the
full dataset is archived on the NCAR Digital Asset Services Hub (DASH) and
may be obtained at https://doi.org/10.5065/83r2-0579 (Pinto
et al., 2020a).
River-enhanced non-linear overtide variations in river estuaries
Authors: Guo Leicheng , Zhu Chunyan , Cai Huayang , Wang Zheng Bing , Townend Ian , He Qing
Published: February 2021

Abstract. Tidal waves traveling into estuaries are modulated in amplitude and shape due to bottom friction, funneling planform and river discharge. The role of river discharge on damping incident tides has been well-documented, whereas our understanding of the impact on overtide is incomplete. Inspired by findings from tidal data analysis, in this study we use a schematized estuary model to explore the variability of overtide under varying river discharge. Model results reveal significant M4 overtide generated inside the estuary. Its absolute amplitude decreases and increases in the upper and lower parts of the estuary, respectively, with increasing river discharge. The total energy of the M4 tide integrated throughout the estuary reaches a transitional maximum when the river discharge to tidal mean discharge (R2T) ratio is close to unity. We further identify that the quadratic bottom stress plays a dominant role in governing the M4 variations through strong river-tide interaction. River flow enhances the effective bottom stress and dissipation of the principal tides, and reinforces energy transfer from principal tide to overtide. The two-fold effects explain the nonlinear M4 variations and the intermediate maximum threshold. The model results are consistent with data analysis in the Changjiang and Amazon River estuaries and highlight distinctive tidal behaviors between upstream tidal rivers and downstream tidal estuaries. The new findings inform study of compound flooding risk, tidal asymmetry, and sediment transport in river estuaries.
Multilayer-HySEA model validation for landslide-generated tsunamis – Part 1: Rigid slides
Authors: Macías Jorge , Escalante Cipriano , Castro Manuel J.
Published: February 2021

Abstract. This paper is devoted to benchmarking the Multilayer-HySEA model using laboratory
experimental data for landslide-generated tsunamis.
This article deals with rigid slides, and the second part, in a companion paper,
addresses granular slides.
The US National Tsunami Hazard and Mitigation Program (NTHMP) has proposed the experimental data used
and established for the NTHMP Landslide Benchmark Workshop, held in January 2017 at Galveston (Texas).
The first three benchmark problems proposed in this workshop deal with rigid slides. Rigid slides must be simulated as a moving
bottom topography, and, therefore, they must be modeled as a prescribed boundary condition.
These three benchmarks are used here to validate the Multilayer-HySEA model.
This new HySEA model consists of an efficient hybrid finite-volume–finite-difference implementation on GPU architectures of a non-hydrostatic multilayer model.
A brief description of model equations, dispersive properties, and the numerical scheme is included.
The benchmarks are described and the numerical results compared against the lab-measured data for each of them.
The specific aim is to validate this new code for tsunamis generated by rigid slides.
Nevertheless, the overall objective of the current benchmarking effort is to produce a ready-to-use numerical
tool for real-world landslide-generated tsunami hazard assessment.
This tool has already been used to reproduce the Port Valdez, Alaska, 1964 and Stromboli, Italy, 2002 events.
The GRISLI-LSCE contribution to the Ice Sheet Model Intercomparison Project for phase 6 of the Coupled Model Intercomparison Project (ISMIP6) – Part 2: Projections of the Antarctic ice sheet evolution by the end of the 21st century
Authors: Quiquet Aurélien , Dumas Christophe
Published: February 2021

Abstract. The Antarctic ice sheet's contribution to global sea level rise over the 21st century is of primary societal importance and remains largely uncertain as of yet. In particular, in the recent literature, the contribution of the Antarctic ice sheet by 2100 can be negative (sea level fall) by a few centimetres or positive (sea level rise), with some estimates above 1 m. The Ice Sheet Model Intercomparison Project for the Coupled Model Intercomparison Project – phase 6 (ISMIP6) aimed at reducing the uncertainties in the fate of the ice sheets in the future by gathering various ice sheet models in a common framework. Here, we present the GRISLI-LSCE (Grenoble Ice Sheet and Land Ice model of the Laboratoire des Sciences du Climat et de l'Environnement) contribution to ISMIP6-Antarctica. We show that our model is strongly sensitive to the climate forcing used, with a contribution of the Antarctic ice sheet to global sea level rise by 2100 that ranges from −50 to +150 mm sea level equivalent (SLE). Future oceanic warming leads to a decrease in thickness of the ice shelves, resulting in grounding-line retreat, while increased surface mass balance partially mitigates or even overcompensates the dynamic ice sheet contribution to global sea level rise.
Most of the ice sheet changes over the next century are dampened under low-greenhouse-gas-emission scenarios. Uncertainties related to sub-ice-shelf melt rates induce large differences in simulated grounding-line retreat, confirming the importance of this process and its representation in ice sheet models for projections of the Antarctic ice sheet's evolution.
Questionnaire
Authors: Hosseini Sahar
Published: February 2021

Response to the questionnaire
Questionnaire
Authors: Rajagopalan Mrinalini
Published: February 2021

Response to the questionnaire: “Stationary Women Moving Through the World: The Church of the Sacred Heart of Jesus, Calcutta, founded by Mrs. Pascoa Barretto de Souza, 1834”
Painting as a Modern Art in Early Renaissance Italy
Authors: Nygren Christopher J.
Published: February 2021

Robert Brennan, Painting as a Modern Art in Early Renaissance Italy. London: Harvey Miller, Renovatio Artium Series in the Arts of the Renaissance, 2019. 366 pp; 11 b/w ills. + 115 color ills., 1 b/w table. Hardcover  €125

(9781912554003)
Five Pressing Questions on the Ideal City
Authors: Garcia Cruz , Frankowski Nathalie
Published: February 2021

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