A note on K4-closures in Hamiltonian graph theory

Let G=(V, E) be a 2-connected graph. We call two vertices u and v of G a K4-pair if u and v are the vertices of degree two of an induced subgraph of G which is isomorphic to K4 minus an edge. Let x and y be the common neighbors of a K4-pair u, v in an induced K4−e. We prove the following result: If N(x)N(y)N(u)N(v){u,v}, then G is hamiltonian if and only if G+uv is h amiltonian. As a consequence, a claw-free graph G is hamiltonian if and only if G+uv is hamiltonian, where u,v is a K4-pair. Based on these results we define socalled K4-closures of G. We give infinite classes of graphs with small maximum degree and large diameter, and with many vertices of degree two having complete K4-closures

Feed interventions and skatole deposition

Skatole produced in the large intestine of the pig and the testicular steroid androstenone are the main substances contributing to boar tainted meat from entire male pigs. Boar taint decreases the quality of the meat and is not accepted by consumers. Until now boar taint has been avoided by castrating male pigs. Surgical castration reduces lean meat percentage, growth rate and feed efficiency, and it causes pain to the animal. This constitutes a problem in relation to productivity and welfare. Different attempts on avoiding surgical castration were either not fully effective, not accepted by the market, or they have a long time horizon for implementation. However, when focusing on the effect of feed interventions on boar taint, previous studies have showed a reducing effect through reduced skatole production in the large intestine after a one week application period. Skatole is produced from the microbial fermentation of L-tryptophan in the large intestine. In the literature it is well documented that skatole production in the large intestine is positively correlated with skatole deposition in adipose tissue. Moreover skatole production can be decreased by adding non-digestible and easy fermentable carbohydrates to the feed. However, little is known about skatole producing bacteria from the large intestine of pigs, and how these bacteria can be affected. This thesis reviews skatole production and metabolism in the pig, and how skatole production can be reduced by affecting the microbial production of skatole in the large intestine. A skatole producing bacterium SK9 K4 was isolated from the gastrointestinal tract of pigs. No such bacterium has previously been described. The bacterium was characterised by 16S RNA sequencing, gram stain, analysis of DNA G-C content, cellular fatty acids composition and DNA hybridisation with closely related bacteria. The fermentation of different carbohydrate sources, the growth pattern, the production of organic acids and the skatole production were studied in vitro. The production of skatole in the large intestine was correlated with skatole deposition in adipose tissue. Skatole production could be reduced when adding a minimum of 20 % raw potato starch or 9 % inulin to the feed. The problem concerning deposition of skatole in adipose tissue seems to be solved through the introduction of feed interventions. However high concentrations of androstenone deposited in adipose tissue remains a challenge. Thus, the feed interventions were not fully effective against boar taint. SK9 K4 was described as cells being strictly anaerobic, occurred singly or in pairs and were gram positive. It was identical with an Olsenella sp. strain isolated from the rumen, an uncultured Olsenella sp. clone isolated from sludge and an uncultured bacterium colon isolated from the oral cavity. Moreover SK9 K4 was closely related to Olsenella uli, Olsenella profusa, Olsenella umbonata and Atopobium parvulum. SK9 K4 and O. uli produced skatole from idole-3-acetic acid but not from L-tryptophan. The major fermentation products were lactic acid together with acetic acid and formic acid. SK9 K4 was not able to ferment raw potato starch, inulin and raw corn starch. Thus, when feeding resistant starch or inulin, the growth of skatole producing bacteria might be reduced followed by a reduced ability to produce skatole. The characterisation of a skatole producing bacterium isolated from the gastrointestinal tract of pigs gives the opportunity to further study the bacterium in vivo. Studies should be conducted to investigate the effect of a control diet compared to a diet added a non-digestible and easy fermentable carbohydrate on the growth of SK9 K4 in the large intestine of the pig

PENGARUH DUKUNGAN KELUARGA IBU HAMIL TERHADAP PENCAPAIAN K4 DI BPS DWI SUGITO KABUPATEN MOJOKERTO

Setiap wanita hamil memerlukan sedikitnya empat kali kunjungan selama periode antenatal. Namun sampai saat ini banyak ibu hamil yang belum memeriksakan kehamilan sesuai dengan standart pemeriksaan kehamilan sehingga cakupan K4 masih dibawah target yaitu sebesar 74,5%. Penelitian ini bertujuan untukmengetahui pengaruh antara dukungan keluarga ibu hamil terhadap pencapaian K4 di BPS Dwi Sugito Kabupaten Mojokerto Desain penelitian analitik dengan rancangan cross sectional. Populasi seluruh ibu hamil trimester III di BPS Dwi Sugito Kabupaten Mojokerto sebesar 29 ibu hamil.. Sampel 27 ibu hamil yang diperoleh dengan teknik Simple Random Sampling. Variabel independen dukungan keluarga dan variabel dependen pencapaian K4. Instrumen kuesioner, dengan pengolahan data editing, scoring, coding, tabulating dan dianalisis menggunakan uji Chi-Square dengan tingkat signifikan α= 0,05. Hasil penelitian didapatkan sebagian besar (55,6%) keluarga mendukung. dan sebagian besar (51,9%) tercapai dalam K4. Hasil analisis uji Chi-Square menunjukan hasil = 0,000, tingkat signifikan α=0,05 maka H0 ditolak karena < 0,05 berarti ada pengaruh dukungan keluarga ibu hamil terhadap pencapaian K4 di BPS Dwi Sugito Kab. Mojokerto Penelitian ini dapat disimpulkan bahwa dukungan keluarga sangat berpengaruh terhadap pencapaian K4. Untuk itu disarankan kepada seluruh keluarga, pihak kesehatan serta masyarakat untuk selalu memberi dukungan kepada ibu hamil untuk memeriksakan kehamilannya, sehingga ini berpengaruh terhadap pencapaian K4