title: Using the IEEE 802.11 frame check sequence as a pseudo random number for packet sampling in wireless networks

authors: Raynel, Scott McKenzie

subjects: computer science

abstract: Low power devices such as common wireless router platforms are not capable of performing reliable full packet capture due to resource constraints. In order for such devices to be used to perform link-level measurement on IEEE 802.11 networks, a packet sampling technique is required in order to reliably capture a representative sample of frames. The traditional Berkeley packet filter mechanism found in UNIX-like operating systems does not directly support packet sampling as it provides no way of generating pseudo-random numbers and does not allow a filter program to keep state between invocations. This paper explores the use of the IEEE 802.11 frame check sequence as a source of pseudo-random numbers for use when deciding whether to sample a packet. This theory is tested by analysing the distribution of frame check sequences from a large, real world capture. Finally, a BPF program fragment is presented which can be used to efficiently select packets for sampling.

text: Using the IEEE 802.11 frame check sequence as a pseudo random number for packet sampling in wireless networks Low power devices such as common wireless router platforms are not capable of performing reliable full packet capture due to resource constraints. In order for such devices to be used to perform link-level measurement on IEEE 802.11 networks, a packet sampling technique is required in order to reliably capture a representative sample of frames. The traditional Berkeley packet filter mechanism found in UNIX-like operating systems does not directly support packet sampling as it provides no way of generating pseudo-random numbers and does not allow a filter program to keep state between invocations. This paper explores the use of the IEEE 802.11 frame check sequence as a source of pseudo-random numbers for use when deciding whether to sample a packet. This theory is tested by analysing the distribution of frame check sequences from a large, real world capture. Finally, a BPF program fragment is presented which can be used to efficiently select packets for sampling.

year: 2009

title: Xanthan gum capped ZnO microstars as a promising dietary Zinc supplementation

authors: Ebrahiminezhad, Alireza

subjects: Science & Technology

abstract: Zinc is one of the essential trace elements, and plays an important role in human health. Severe zinc deficiency can negatively affect organs such as the epidermal, immune, central nervous, gastrointestinal, skeletal, and reproductive systems. In this study, we offered a novel biocompatible xanthan gum capped zinc oxide (ZnO) microstar as a potential dietary zinc supplementation for food fortification. Xanthan gum (XG) is a commercially important extracellular polysaccharide that is widely used in diverse fields such as the food, cosmetic, and pharmaceutical industries, due to its nontoxic and biocompatible properties. In this work, for the first time, we reported a green procedure for the synthesis of ZnO microstars using XG, as the stabilizing agent, without using any synthetic or toxic reagent. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) were used to study the structure, morphology, and size of the synthesized ZnO structures. The results showed that the synthesized structures were both hexagonal phase and starlike, with an average particle size of 358 nm. The effect of different dosages of XG-capped ZnO nanoparticles (1–9 mM) against Gram-negative (Escherichia coli) and Gram-positive (Bacillus licheniformis, Bacillus subtilis, and Bacillus sphaericus) bacteria were also investigated. Based on the results, the fabricated XG-capped ZnO microstars showed a high level of biocompatibility with no antimicrobial effect against the tested microorganisms. The data suggested the potential of newly produced ZnO microstructures for a range of applications in dietary supplementation and food fortification.

text: Xanthan gum capped ZnO microstars as a promising dietary Zinc supplementation Zinc is one of the essential trace elements, and plays an important role in human health. Severe zinc deficiency can negatively affect organs such as the epidermal, immune, central nervous, gastrointestinal, skeletal, and reproductive systems. In this study, we offered a novel biocompatible xanthan gum capped zinc oxide (ZnO) microstar as a potential dietary zinc supplementation for food fortification. Xanthan gum (XG) is a commercially important extracellular polysaccharide that is widely used in diverse fields such as the food, cosmetic, and pharmaceutical industries, due to its nontoxic and biocompatible properties. In this work, for the first time, we reported a green procedure for the synthesis of ZnO microstars using XG, as the stabilizing agent, without using any synthetic or toxic reagent. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) were used to study the structure, morphology, and size of the synthesized ZnO structures. The results showed that the synthesized structures were both hexagonal phase and starlike, with an average particle size of 358 nm. The effect of different dosages of XG-capped ZnO nanoparticles (1–9 mM) against Gram-negative (Escherichia coli) and Gram-positive (Bacillus licheniformis, Bacillus subtilis, and Bacillus sphaericus) bacteria were also investigated. Based on the results, the fabricated XG-capped ZnO microstars showed a high level of biocompatibility with no antimicrobial effect against the tested microorganisms. The data suggested the potential of newly produced ZnO microstructures for a range of applications in dietary supplementation and food fortification.

year: 2019

title: Te kiri ka tōkia e te anu: Ko ētahi āhuatanga ki ngā kāinga o Hiruhārama me Te Horo

authors: Parata, Patricia Hekia

subjects: Tangihanga

abstract: He mea waihanga e ahau, tēnei tuhituhinga, i runga i tēnei whakaaro, kia tirohia te hanga, me te āhua o te tangihanga, ki ōku marae e rua, o roto o Ngāti Porou, kei Hiruhārama me Te Horo. Kāore i whāia he wāhanga ki ngā pūtakenga mai o ngā tikanga. Engari, he mea tātaki haere noa iho ko ngā kaupapa tauira o ēnei tikanga. 
He mea raranga anō ngā kōrero nei, kia whiri ai i roto i ngā tauira kōrero nei, te tūpāpaku, te marae, ngā tāngata me ngā tikanga, e pā ana ki a rātau katoa. 
Ahakoa te nui, te huhua noa iho, o ngā tuhituhinga mō te āhua ki tēnei mea, ki te marae, te whaikōrero, te tangihanga, ēnei mea katoa, kore rawa anō nei, tētahi paku tuhituhi kua whakatakotoria i tēnei hanga nei. Ehara hoki tēnei i te tuhituhinga e whai ana i te āhua o ērā o mua atu. 
He mea kohikohi ēnei kōrero, nā ētahi kuia, me ētahi kaumātua, me ngā mea pakeke o tōku nei rohe, ā, he aronga nui nāku ki ngā mea i kite ai au i ngā wā i ahau i te kāinga, me ngā hui i tae ai au mai anō i tōku tamarikitanga. Nō reira, he whakapūteatanga ēnei mea katoa, nō ngā mea katoa i runga ake nei. 
Kua wehewehengia ēnei kōrero kia takoto pēnei ana nā: ko te wāhanga tuatahi, ko te takenga mai o Ngāti Porou, me ngā wehewehenga mai o ngā hapū; ko te wāhanga tuarua, e pā ana ki ngā whakamārama o ngā kupu, arā, te kirimate, te paemate, me te wharemate; tuatoru, ko te whakahoki o te tūpāpaku; tuawhā, kei ngā mahi ki runga i te marae; tuarima, ngā tikanga o te rā nehu; tuaono, ngā mahi whakatutuki. 
Hei whakamutu ake, kua whakarārangitia e ahau, ngā roherohenga mahi, me ngā tūranga e rite ana mō tēnā, mō tēnā, mō tēnā.

text: Te kiri ka tōkia e te anu: Ko ētahi āhuatanga ki ngā kāinga o Hiruhārama me Te Horo He mea waihanga e ahau, tēnei tuhituhinga, i runga i tēnei whakaaro, kia tirohia te hanga, me te āhua o te tangihanga, ki ōku marae e rua, o roto o Ngāti Porou, kei Hiruhārama me Te Horo. Kāore i whāia he wāhanga ki ngā pūtakenga mai o ngā tikanga. Engari, he mea tātaki haere noa iho ko ngā kaupapa tauira o ēnei tikanga. 
He mea raranga anō ngā kōrero nei, kia whiri ai i roto i ngā tauira kōrero nei, te tūpāpaku, te marae, ngā tāngata me ngā tikanga, e pā ana ki a rātau katoa. 
Ahakoa te nui, te huhua noa iho, o ngā tuhituhinga mō te āhua ki tēnei mea, ki te marae, te whaikōrero, te tangihanga, ēnei mea katoa, kore rawa anō nei, tētahi paku tuhituhi kua whakatakotoria i tēnei hanga nei. Ehara hoki tēnei i te tuhituhinga e whai ana i te āhua o ērā o mua atu. 
He mea kohikohi ēnei kōrero, nā ētahi kuia, me ētahi kaumātua, me ngā mea pakeke o tōku nei rohe, ā, he aronga nui nāku ki ngā mea i kite ai au i ngā wā i ahau i te kāinga, me ngā hui i tae ai au mai anō i tōku tamarikitanga. Nō reira, he whakapūteatanga ēnei mea katoa, nō ngā mea katoa i runga ake nei. 
Kua wehewehengia ēnei kōrero kia takoto pēnei ana nā: ko te wāhanga tuatahi, ko te takenga mai o Ngāti Porou, me ngā wehewehenga mai o ngā hapū; ko te wāhanga tuarua, e pā ana ki ngā whakamārama o ngā kupu, arā, te kirimate, te paemate, me te wharemate; tuatoru, ko te whakahoki o te tūpāpaku; tuawhā, kei ngā mahi ki runga i te marae; tuarima, ngā tikanga o te rā nehu; tuaono, ngā mahi whakatutuki. 
Hei whakamutu ake, kua whakarārangitia e ahau, ngā roherohenga mahi, me ngā tūranga e rite ana mō tēnā, mō tēnā, mō tēnā.

year: 1983